JP2012067272A - Method for producing cellulose acylate film, cellulose acylate film, polarizing plate, liquid crystal display device, and optical compensation film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for producing a cellulose acylate film in which the retardation is controlled without high drawing ratio and also without the promotion of the crystallization of the cellulose acylate.SOLUTION: The method for producing the cellulose acylate film at least includes: a casting step of forming a web by casting a fluid, comprising a cellulose acylate, aromatic group-containing oligomer, and solvent, onto a support; a stretching step of stretching the web whose amount of residual solvent C1 is 20-300 mass%, thereby to orient at least molecules of the aromatic group-containing oligomer along the stretching direction; and a heat-treatment step of subjecting 10-120 mass% of the stretched web of the amount of residual solvent C2 (C2≤C1) to a heat treatment with a film surface temperature of 40-200°C, thereby to at least increase the orientation degree of the molecules of the aromatic group-containing oligomer.

Description

  The present invention relates to a method for producing a cellulose acylate film, and a cellulose acylate film produced by the method. The cellulose acylate film produced by the method of the present invention exhibits a high Re and a high Rth at a low stretch ratio, and is useful as an optical member for liquid crystal display devices of various modes.

  2. Description of the Related Art Conventionally, cellulose acylate films have been used in various modes of liquid crystal display devices as optical members of liquid crystal display devices, for example, optical compensation film supports, polarizing plate protective films, and the like. When used in such optical applications, control of the optical anisotropy is important. On the other hand, with cellulose acylate alone, there is a limit to the optical properties that can be realized, and in order to achieve high Re or high Rth, a retardation developer is added and stretched to achieve the desired optical properties. The fact is. However, in these methods, in order to realize a high Re or a high Rth, it is necessary to perform a stretching process at a high stretching ratio, and a phenomenon such as deterioration of the film surface shape and the axis may occur. In addition, an off-line drawing machine is required, and a large amount of capital investment may be required. In addition, many of these additives are low-molecular compounds, and when the stretching temperature is increased to increase the stretching ratio, phenomena such as volatilization or crying out of the film may occur during the manufacturing process. .

  A film for optical use is required to have no surface unevenness and good surface shape in addition to optical characteristics. Conventionally, phosphorus-based plasticizers such as triphenyl phosphate have been often used for the purpose of improving the surface shape of cellulose acylate films. However, with respect to the phosphorus-based plasticizer, as described above, phenomena such as crying out during the production process may occur. Patent Document 1 discloses a method for producing a transparent polymer film in which a predetermined plasticizer having a number average molecular weight of 500 to 1000 is added and the expression of retardation can be adjusted. This method includes a step of heat treatment at a temperature equal to or higher than the crystallization temperature of the polymer before the heat treatment.

JP 2010-107960 A

As described in [0174] of Patent Document 1, the method of Patent Document 1 promotes the crystallization of cellulose acylate by heat-treating the polymer film at a temperature Tc (crystallization temperature) or higher. The foundation is adjusted. However, adjustment of retardation by crystallization of cellulose acylate requires heat treatment at a temperature higher than the crystallization temperature, and there is a limit to in-line production, and production of a high Re and high Rth film is possible. It can be difficult.
The present invention provides a novel method for producing a cellulose acylate film having an adjusted retardation without requiring a high draw ratio and without accelerating crystallization of the cellulose acylate. It is an object of the present invention to provide a cellulose acylate film produced by the above, a polarizing plate having the cellulose acylate film, a liquid crystal display device, and an optical compensation film.

一般式（ＩＸ）中、Ｎは、窒素原子を表し、Ｒ¹〜Ｒ⁷は、それぞれ水素原子又は置換基を表す。
［１３］ 下記一般式（ＩＸａ−ａ）、（ＩＸａ−ｂ）、（ＩＸａ−ｃ）、および（ＩＸａ−ｄ）で表されるいずれかの化合物と、前記一般式（ＩＸ）で表されるメロシアニン系化合物とを混合して使用することを特徴とする［１２］の方法；

一般式（ＩＸａ−ａ）中、Ｒ^6a及びＲ^7aは、それぞれ水素原子又は置換基を表し；一般式（ＩＸａ−ｂ）中、Ｒ^6b及びＲ^7bは、それぞれ水素原子又は置換基を表し；一般式（ＩＸａ−ｃ）中、Ｒ^6C及びＲ^7Cは、それぞれ水素原子又は置換基を表し；一般式（ＩＸａ−ｄ）中、Ｒ¹¹及びＲ¹²は、それぞれ、アルキル基、アリール基、シアノ基、又は−ＣＯＯＲ¹³を表すか、互いに結合して窒素原子を含む環を表し；Ｒ^1３は、アルキル基、アリール基、又はヘテロ環基を表す。
［１４］ さらに、下記一般式（ＩＩ）で表されるトリアジン系化合物を含有することを特徴とする［１］〜［１３］のいずれかの方法；

一般式（ＩＩ）中、Ｘ¹は、−ＮＲ⁴−、−Ｏ−又は−Ｓ−を表し；Ｘ²は、−ＮＲ⁵−、−Ｏ−又は−Ｓ−を表し；Ｘ³は、−ＮＲ⁶−、−Ｏ−又は−Ｓ−を表し；Ｒ¹、Ｒ²及びＲ³は、それぞれ、アルキル基、アルケニル基、アリール基又は複素環基を表し；Ｒ⁴、Ｒ⁵及びＲ⁶は、それぞれ、水素原子、アルキル基、アルケニル基、アリール基又は複素環基を表す。
［１５］ ［１］〜［１４］のいずれかの方法によって製造されるセルロースアシレートフィルムであって、波長５５０ｎｍにおける面内レターデーションＲｅ（５５０）が５〜５０ｎｍであり、及び波長５５０ｎｍにおける厚み方向レターデーションＲｔｈ（５５０）が９０〜１５０ｎｍであることを特徴とするセルロースアシレートフィルム。
［１６］ ［１］〜［１４］のいずれかの方法によって製造されるセルロースアシレートフィルムであって、波長５５０ｎｍにおける面内レターデーションＲｅ（５５０）が５〜２０ｎｍであり、及び波長５５０ｎｍにおける厚み方向レターデーションＲｔｈ（５５０）が９０〜１５０ｎｍであることを特徴とするセルロースアシレートフィルム。
［１７］ 長尺状であって、長手方向に対して直交する方向にセルロースアシレートの分子が配向していることを特徴とする［１５］又は［１６］のセルロースアシレートフィルム。
［１８］ ［１］〜［１４］のいずれかの方法によって製造されるセルロースアシレートフィルムであって、波長５５０ｎｍにおける厚み方向レターデーションＲｔｈ（５５０）と波長４５０ｎｍにおける厚み方向レターデーションＲｔｈ（４５０）が下記式（１）を満たすことを特徴とする［１５］〜［１７］のいずれかのセルロースアシレートフィルム。
０．９０ ＜ Ｒｔｈ（４５０） ／ Ｒｔｈ（５５０） ≦ １．５ （１）
［１９］ 偏光子と、［１５］〜［１８］のいずれかのセルロースアシレートフィルムとを少なくとも有することを特徴とする偏光板。
［２０］ 前記偏光子の吸収軸と、前記セルロースアシレートフィルムの遅相軸とが直交していることを特徴とする［１９］の偏光板。
［２１］ ［１５］〜［１８］のいずれかのセルロースアシレートフィルム、及び／又は［１９］又は［２０］に記載の偏光板を少なくとも有することを特徴とする液晶表示装置。
［２２］ 捩れ配向モード又は垂直配向モードであることを特徴とする［２１］に記載の液晶表示装置。
［２３］ ［１５］〜［１８］のいずれかのセルロースアシレートフィルムと重合性液晶化合物を含有する組成物とからなる光学異方性層を有することを特徴とする光学補償フィルム。 As a result of intensive studies by the present inventors in order to solve the above-mentioned problems, optical properties that were difficult to achieve in the past were obtained by using aromatic-containing oligomers as plasticizers and actively utilizing the molecular orientation of the oligomers. The present inventors have obtained knowledge that a cellulose acylate film exhibiting the above can be stably produced, and have completed the present invention.
That is, the means for solving the above problems are as follows.
[1] A casting step of casting a liquid containing cellulose acylate, an aromatic group-containing oligomer and a solvent on a support to form a web;
A stretching step of stretching the web and orienting at least the molecules of the aromatic group-containing oligomer in the stretching direction;
A heat treatment step of heat-treating the stretched web to increase the degree of molecular orientation of at least the aromatic-containing oligomer;
A method for producing a cellulose acylate film, comprising:
[2] The aromatic group-containing oligomer is an oligomer of a polycondensation ester containing a residue of at least one aromatic dicarboxylic acid and a residue of at least one aliphatic diol [1] ]the method of.
[3] The method according to [1] or [2], wherein the aromatic group-containing oligomer has a number average molecular weight of 500 to 2,000.
[4] The method according to any one of [1] to [3], wherein the liquid contains 3 to 20 parts by mass of the aromatic-containing oligomer with respect to 100 parts by mass of the cellulose acylate.
[5] The method according to any one of [1] to [4], wherein in the stretching step, a web having a residual solvent amount of 20 to 300% by mass is stretched at a film surface temperature of −30 to 80 ° C.
[6] The method according to any one of [1] to [5], wherein in the heat treatment step, a web having a residual solvent amount of 10 to 120% by mass is heat-treated at a film surface temperature of 40 to 200 ° C.
[7] The method according to any one of [1] to [6], wherein in the stretching step, the web is stretched at a stretch ratio of 1 to 50%.
[8] The method according to any one of [1] to [7], wherein the liquid is cast onto a drum surface.
[9] The method according to any one of [1] to [8], wherein in the stretching step, the web is stretched in a direction orthogonal to the casting direction.
[10] The method according to any one of [1] to [9], wherein the web is not stretched after the stretching step.
[11] The method according to any one of [1] to [10], wherein the liquid contains 0.2 to 20% by mass of a wavelength dispersion adjusting agent having an absorption maximum at 250 to 400 nm.
[12] The method according to [11], wherein the wavelength dispersion adjusting agent is a merocyanine compound represented by the following general formula (IX):

In General Formula (IX), N represents a nitrogen atom, and R ^{1 to} R ⁷ each represents a hydrogen atom or a substituent.
[13] Any of the compounds represented by the following general formula (IXa-a), (IXa-b), (IXa-c), and (IXa-d), and the general formula (IX) The method according to [12], wherein the mixture is used in combination with a merocyanine compound;

In general formula (IXa-a), R ^<6a> and R ^<7a> respectively represent a hydrogen atom or a substituent; In general formula (IXa-b), R ^<6b> and R ^<7b> respectively represent a hydrogen atom or a substituent; In general formula (IXa-c), R ^6C and R ^7C each represent a hydrogen atom or a substituent; in general formula (IXa-d), R ¹¹ and R ¹² represent an alkyl group, an aryl group, and cyano, respectively. Represents a group, or —COOR ¹³ , or represents a ring containing a nitrogen atom bonded to each other; R ¹³ represents an alkyl group, an aryl group, or a heterocyclic group;
[14] The method according to any one of [1] to [13], further comprising a triazine compound represented by the following general formula (II):

In general formula (II), X ¹ represents —NR ⁴ —, —O— or —S—; X ² represents —NR ⁵ —, —O— or —S—; X ³ represents — NR ^6- , -O- or -S-; R ¹ , R ² and R ³ each represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; R ⁴ , R ⁵ and R ⁶ are Respectively represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
[15] A cellulose acylate film produced by any one of the methods [1] to [14], having an in-plane retardation Re (550) at a wavelength of 550 nm of 5 to 50 nm, and a thickness at a wavelength of 550 nm. A cellulose acylate film having a directional retardation Rth (550) of 90 to 150 nm.
[16] A cellulose acylate film produced by any one of the methods [1] to [14], having an in-plane retardation Re (550) at a wavelength of 550 nm of 5 to 20 nm, and a thickness at a wavelength of 550 nm. A cellulose acylate film having a directional retardation Rth (550) of 90 to 150 nm.
[17] The cellulose acylate film of [15] or [16], wherein the cellulose acylate molecule is elongated and has molecules of cellulose acylate oriented in a direction perpendicular to the longitudinal direction.
[18] A cellulose acylate film produced by any one of the methods [1] to [14], wherein the thickness direction retardation Rth (550) at a wavelength of 550 nm and the thickness direction retardation Rth (450) at a wavelength of 450 nm Satisfy | fills following formula (1), The cellulose acylate film in any one of [15]-[17] characterized by the above-mentioned.
0.90 <Rth (450) / Rth (550) ≦ 1.5 (1)
[19] A polarizing plate comprising at least a polarizer and the cellulose acylate film of any one of [15] to [18].
[20] The polarizing plate according to [19], wherein an absorption axis of the polarizer and a slow axis of the cellulose acylate film are perpendicular to each other.
[21] A liquid crystal display device comprising at least the cellulose acylate film according to any one of [15] to [18] and / or the polarizing plate according to [19] or [20].
[22] The liquid crystal display device according to [21], which is a twist alignment mode or a vertical alignment mode.
[23] An optical compensation film comprising an optically anisotropic layer comprising the cellulose acylate film of any one of [15] to [18] and a composition containing a polymerizable liquid crystal compound.

  According to the present invention, there is provided a novel method for producing a cellulose acylate film having an adjusted retardation without requiring a high stretch ratio and without requiring the crystallization of cellulose acylate. And the cellulose acylate film manufactured by the said method, the polarizing plate which has it, a liquid crystal display device, and an optical compensation film can be provided.

It is a cross-sectional schematic diagram of an example of the twist orientation mode liquid crystal display device which has the cellulose acylate film of this invention. It is a cross-sectional schematic diagram of an example of the vertical alignment mode liquid crystal display device which has the cellulose acylate film of this invention.

Below, the manufacturing method of the cellulose acylate film of this invention and the cellulose acylate film manufactured by this method are demonstrated in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
In the present specification, Re (λ) and Rth (λ) represent the values of Re and Rth at the wavelength λnm, respectively. Note that Re and Rth respectively represent Re (550) and Rth (550) without any particular limitation.

1. The present invention relates to a casting process in which a liquid containing cellulose acylate, an aromatic group-containing oligomer and a solvent is cast on a support to form a web, and a residual solvent amount C1 is 20 A stretching step of stretching a web of ˜300% by mass to orient at least molecules of the aromatic group-containing oligomer in the stretching direction, and a web after stretching having a residual solvent amount C2 (where C1 <C2) is 10 to 120% by mass At least a heat treatment step for increasing the degree of orientation of the molecules of the aromatic-containing oligomer and for orienting the molecules of the cellulose acylate in the stretching direction. The present invention relates to a method for producing a cellulose acylate film.
In the production method of the present invention, at least the aromatic group-containing oligomer molecules are oriented in the stretching direction in the stretching step, and in the heat treatment step, at least the aromatic-containing oligomer molecules are suppressed while suppressing crystallization of cellulose acylate. While increasing the degree of orientation, the molecules of cellulose acylate are oriented in the stretching direction. As a result, it was difficult to adjust the retardation by promoting the crystallization of the cellulose acylate in the past, or adjusting the retardation by promoting the orientation of the retardation developer at the in-line stretch ratio. A film having a high Re and a high Rth can be produced stably.

  Further, in the method of promoting crystallization of cellulose acylate, since it is necessary to heat at a certain high temperature for a long time for crystallization, there is a problem that the additive is volatilized in terms of energy. . In the method of the present invention, it is not necessary to promote the crystallization of cellulose acylate, and the heat treatment rather suppresses the crystallization of cellulose acylate, and increases the degree of orientation of the predetermined oligomer molecules oriented in the stretching step. Therefore, the heat treatment temperature may be lower than that of the method for promoting crystallization. Therefore, energy efficiency is good and volatilization of the additive can be suppressed.

Hereafter, each process of the method of this invention is demonstrated.
Casting process:
In the present invention, a liquid containing cellulose acylate, an aromatic group-containing oligomer and a solvent (hereinafter sometimes referred to as “dope”) is prepared, and the liquid is cast on a support to form a web. . In the method of the present invention, a cellulose acylate film containing cellulose acylate as a main component and containing an aromatic group-containing oligomer as an additive is produced. The cellulose acylate and aromatic-containing oligomer that can be used in the method of the present invention will be described later. Here, the “web” means a cellulose acylate film containing a certain amount of solvent after casting and before being completely dried.

In the casting step, for example, the dope is cast on the support from the slit of the casting die. The support is, for example, in the form of a belt or a drum, and the dope is cast on the surface of the support that is running in the casting direction. At the time of casting, a force acts in the casting direction, so that the cellulose acylate and aromatic-containing oligomer molecules in the dope tend to be oriented to some extent in the casting direction. The degree of force acting on molecules during casting is a value calculated from the following equation (hereinafter referred to as “PIT draw”) from the rotation speed of the belt or drum (support speed) and the web conveyance speed (film formation speed). The unit can be understood as an index.
PIT draw = film forming speed / support speed

  In the method of the present invention, since the predetermined oligomer is oriented in the stretching direction in a stretching step described later, it is also referred to as a casting direction (in this specification, “conveying direction” and “MD direction”, both of which are in the same direction. In a drawing process in which the drawing direction in the drawing step described below does not match, for example, a drawing in a direction perpendicular to the casting direction, the casting is performed under a condition that the force acting on the material is low during casting. Specifically, the PIT draw is preferably about 101 to 110%, more preferably 101 to 105%. On the other hand, there is no particular limitation on the PIT draw in an aspect in which the casting direction coincides with the stretching direction in the stretching process described later.

  The support on which the dope is cast is preferably a metal support, and for example, a metal band or a metal drum can be used. According to the method of the present invention, a film having desired optical characteristics can be produced with high productivity by using a drum as a support.

  In the casting step, the dope may be cast in a single layer on a support, or the dope and optionally one or more other types of dopes may be cast in a laminate of two or more layers. May be. In the latter form, the film may be produced while casting and laminating the dope and one or more other types of dopes from a plurality of casting openings provided at intervals in the traveling direction of the support. For example, the methods described in, for example, JP-A-61-158414, JP-A-1-122419, and JP-A-11-198285 can be applied. Alternatively, the dope and, if desired, one or more other dopes may be cast from two casting ports to form a film. For example, JP-B-60-27562, JP-A-61-94724 The methods described in JP-A-61-947245, JP-A-61-104813, JP-A-61-158413, and JP-A-6-134933 can be used. Further, a casting method described in JP-A-56-162617 may be carried out by wrapping a flow of a high viscosity dope with a low viscosity dope and simultaneously extruding the high and low viscosity dope. Furthermore, it is also a preferable aspect that the outer dope described in JP-A-61-94724 and JP-A-61-94725 contains a larger amount of an alcohol component which is a poor solvent than the inner dope. . Alternatively, using two casting ports, the film cast on the support is peeled off by the first casting port, and the second casting is performed on the side that is in contact with the support surface to produce a film. For example, it is a method described in Japanese Patent Publication No. 44-20235.

  In an embodiment in which a plurality of dopes are cast in a laminated form, in order to give each layer a function, a dope corresponding to the function can be used. For example, a dope containing a material for forming an adhesive layer, a dye layer, an antistatic layer, an antihalation layer, a UV absorbing layer, a polarizing layer, and the like can be cast at the same time.

In the co-casting mode in which a plurality of dopes are cast from a casting port, a high-viscosity dope can be cast on the support at the same time, and the planarity is improved and an excellent planar film can be produced. By using a thick dope, a reduction in drying load could be achieved, and the film production speed could be further increased.
In the co-casting aspect, the thickness of the inner layer and the outer layer is not particularly limited, but preferably the outer layer is preferably 1 to 50% of the total film thickness, more preferably 2 to 30%. Is the thickness. Here, in the case of co-casting with three or more layers, the total thickness of the layer in contact with the support and the layer in contact with the air side is defined as the outer thickness. In the co-casting mode, a cellulose acylate film having a laminated structure can be produced by co-casting dopes having different additive concentrations such as the above-mentioned plasticizer, ultraviolet absorber and matting agent. For example, a cellulose acylate film having a structure of skin layer / core layer / skin layer can be produced. For example, the matting agent can be contained in the skin layer in a large amount or only in the skin layer. The plasticizer and the ultraviolet absorber can be contained in the core layer more than the skin layer, and may be contained only in the core layer. In addition, the type of plasticizer and ultraviolet absorber can be changed between the core layer and the skin layer. For example, the skin layer contains a low-volatile plasticizer and / or an ultraviolet absorber, and the core layer has excellent plasticity. It is also possible to add a plasticizer or an ultraviolet absorber excellent in ultraviolet absorption. Moreover, it is also a preferable aspect to contain a peeling accelerator only in the skin layer on the metal support side. It is also preferable to add more alcohol, which is a poor solvent, to the skin layer than the core layer in order to cool the metal support by the cooling drum method to gel the solution. The Tg of the skin layer and the core layer may be different, and the Tg of the core layer is preferably lower than the Tg of the skin layer. In addition, the dope viscosity during casting may be different between the skin layer and the core layer, and it is preferable that the dope viscosity of the skin layer is smaller than the dope viscosity of the core layer. It may be smaller.

Stretching process:
Next, the web is stretched so that at least the molecules of the aromatic group-containing oligomer are oriented in the stretching direction. The residual solvent amount C1 of the web is preferably 20 to 300% by mass. Here, the “residual solvent amount” of the web can be calculated based on the following formula. Moreover, it can calculate similarly about the amount of residual solvents in the heat processing process mentioned later.
Residual solvent amount (% by mass) = {(MN) / N} × 100
[In the formula, M represents the mass of the web immediately before being inserted into the stretching zone, and N represents the mass when the web immediately before being inserted into the stretching zone was dried at 120 ° C. for 2 hours. ]

  Residual solvent amount C1 is in the above range, and by stretching a web containing a large amount of solvent, a predetermined oligomer present in the web as an additive is oriented to some extent with its molecular long axis coinciding with the stretching direction. Can do. If the residual solvent amount C1 exceeds 300% by mass, the molecules tend to be difficult to align, and if it is less than 20% by mass, the web may be hard and difficult to stretch. The residual solvent amount C1 is more preferably 20 to 250% by mass, and further preferably 20 to 150% by mass.

In order to increase the degree of orientation of the predetermined oligomer molecules in the heat treatment step described later, the draw ratio in this step may be such that the molecules of the predetermined oligomers are aligned. For example, in an aspect in which the film is stretched in a direction perpendicular to the casting direction, the draw ratio is preferably 1 to 50%, and more preferably 1 to 20%. Moreover, in the aspect extended | stretched in the same direction as a casting direction, it is preferable that a draw ratio is 1 to 300%, and it is more preferable that it is 1 to 200%.
In the present specification, the “stretch ratio (%)” means that determined by the following formula, but is not limited to the method of directly measuring the length, and the stretch ratio determined by the following formula: Other methods that can achieve the same result as can be adopted.
Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / Length before stretching

  There are no particular restrictions on the temperature during stretching. It is preferable to carry out at a temperature that promotes the orientation of the predetermined oligomer molecules in the stretching direction. In general, the film surface temperature of the web is preferably −30 to 80 ° C., more preferably 25 to 80 ° C.

  In the method of the present invention, the orientation direction of cellulose acylate and the orientation direction of oligomer molecules in the film finally produced, that is, the in-plane slow axis direction of the film, are determined by the stretching direction in the stretching step. . For example, when continuously producing a long cellulose acylate by the method of the present invention, the casting direction becomes the longitudinal direction. When stretching is performed along a direction orthogonal to the casting direction (hereinafter sometimes referred to as “TD direction”), cellulose acylate and oligomer molecules are oriented in a direction orthogonal to the longitudinal direction, and as a result A film having an in-plane slow axis along the direction perpendicular to the longitudinal direction can be produced, and if stretching is performed in the casting direction, cellulose acylate and oligomer molecules are oriented with respect to the longitudinal direction. As a result, a film having an in-plane slow axis along the longitudinal direction can be produced.

  Stretching in the TD direction can be carried out by gripping both ends of the web with pin-shaped tenters and spreading in the TD direction. Stretching in the MD direction can be performed by PIT draw. The stretching treatment may be performed in one stage or in two or more stages.

  When a long film is bonded to a long polarizing film (generally having a transmission axis in the longitudinal direction) to produce a polarizing plate, the direction orthogonal to the longitudinal direction It is preferable to use a film having an in-plane slow axis. Therefore, in the aspect which manufactures the elongate cellulose acylate film bonded with a polarizing film with a roll-to-roll, in the said extending process, extending | stretching process is performed in the direction orthogonal to a casting direction. preferable. However, instead of roll-to-roll, in a mode of pasting to the polarizing film by a batch laminating method or the like, even if stretched in any direction, it can be pasted in a preferred relationship by axial alignment at the time of pasting. it can.

Heat treatment process:
Next, after the stretching process, the web is heat-treated under predetermined conditions. By this heat treatment, the degree of orientation of the predetermined oligomer oriented in the stretching step is increased. As long as the degree of orientation of the predetermined oligomer can be increased, the heat treatment conditions are not particularly limited. Factors affecting the orientation of the oligomer during the heat treatment are mainly the film surface temperature of the web during the heat treatment and the residual solvent amount of the web during the heat treatment. An example of a heat treatment condition for stably increasing the degree of orientation of a predetermined oligomer is a heat treatment in which a stretched web having a residual solvent amount C2 of 10 to 120 mass% is performed at a film surface temperature of 40 to 200 ° C. The residual solvent amount C2 of the web at the time of heat treatment is less than the residual solvent amount C1 of the web in the stretching step, that is, 10 to 120% by mass on the assumption that the relationship of C2 ≦ C1 is satisfied. preferable. If the residual solvent amount C2 exceeds 120% by mass or less than 10% by mass, the degree of orientation of the oligomer tends to be difficult to increase, and the target retardation may not be obtained. The residual solvent amount C2 is preferably 20 to 80% by mass, and more preferably 20 to 60% by mass.

The heat treatment step is preferably performed while suppressing the crystallization of cellulose acylate. Therefore, it is preferable to heat-treat at a temperature lower than the heat-treating temperature that promotes crystallization of cellulose acylate. Specifically, it is preferable to heat-treat at a film surface temperature of 40 to 100 ° C. More preferably, heat treatment is performed at 100 ° C.
In order to suppress crystallization of cellulose acylate, the film surface temperature during heat treatment is preferably less than the crystallization temperature of the web before heat treatment.

  In the heat treatment, for example, a method of passing a web through a zone set at a predetermined temperature, a method of applying hot air at a predetermined temperature, a method of irradiating with heat rays, or a roll set at a predetermined temperature is brought into contact with the web. It can be implemented by a method or the like.

In the present invention, since the cellulose acylate film having the above optical properties can be produced without requiring a stretching step after the heat treatment, a drum is used as a casting support, and the number of steps is continuously reduced in a short time. It can be produced in the form of a long film. It is also possible to manufacture in-line, and productivity can be significantly improved.
For example, the PIT draw is set to 101 to 200% and the support speed is set to 50 to 200 m / min without adding an additive that affects the optical characteristics other than the predetermined oligomer. It is also possible to produce an Rth cellulose acylate film in-line.

  As long as the effect of this invention is not impaired, you may implement one or more processes chosen from extending | stretching, heat processing, surface treatment, etc. to the obtained cellulose acylate film as needed after the said heat processing process.

Next, preparation of the dope used in the casting step of the method of the present invention will be described.
The dope used for the casting step contains cellulose acylate, an aromatic group-containing oligomer, and a solvent. The cellulose acylate and the oligomer are preferably dissolved in a solvent. In the dope, the cellulose acylate concentration is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, and particularly preferably 15 to 30% by mass. The cellulose acylate concentration can be adjusted to a predetermined concentration at the stage of dissolving the cellulose acylate in a solvent. Moreover, after preparing a low concentration (for example, 4-14 mass%) solution previously, you may concentrate by evaporating a solvent. Furthermore, after preparing a high concentration solution in advance, it may be diluted. Further, the concentration of the predetermined oligomer is preferably 0.5 to 4% by mass, and more preferably 1 to 3% by mass.
Hereinafter, each component will be described.

solvent:
The solvent used for preparing the dope used in the casting step may be one type or two or more types. As the main solvent, an organic solvent which is a good solvent for cellulose acylate can be preferably used. As such an organic solvent, an organic solvent having a boiling point of 80 ° C. or lower is more preferable from the viewpoint of reducing the drying load. The boiling point of the organic solvent is more preferably 10 to 80 ° C, and particularly preferably 20 to 60 ° C. Moreover, the organic solvent whose boiling point is 30-45 degreeC depending on the case can also be used suitably as said main solvent. A solvent containing 1 to 15% by mass of a solvent having a low boiling point with a halogenated hydrocarbon and having a boiling point of 95 ° C. or higher with respect to the total solvent can be used. It is preferable to use, and it is more preferable to use a solvent containing 1.5 to 8% by mass. And it is preferable that the solvent whose boiling point is 95 degreeC or more is a poor solvent of a cellulose acylate. Specific examples of the solvent having a boiling point of 95 ° C. or higher include solvents having a boiling point of 95 ° C. or higher among the specific examples of the “organic solvent used in combination with the main solvent” described later, but butanol, pentanol, It is preferable to use 1,4-dioxane. Furthermore, the solvent of the polymer solution used in the present invention more preferably contains an alcohol. In addition, when said "solvent whose boiling point is 95 degreeC or more" is alcohol, such as butanol, the content is also counted by the alcohol content here.

  Examples of such a main solvent include halogenated hydrocarbons, esters, ketones, ethers, alcohols, and hydrocarbons, and these may have a branched structure or a cyclic structure. The main solvent may have two or more functional groups of esters, ketones, ethers and alcohols (that is, —O—, —CO—, —COO—, —OH). Furthermore, the hydrogen atom in the hydrocarbon portion of the ester, ketone, ether and alcohol may be substituted with a halogen atom (particularly a fluorine atom). In addition, the main solvent of the polymer solution in the present invention used for the production of the cellulose acylate film used in the production method of the present invention, when composed of a single solvent, indicates that solvent, from a plurality of solvents In this case, the solvent having the highest mass fraction among the constituent solvents is shown. Preferred examples of the main solvent include halogenated hydrocarbons.

As said halogenated hydrocarbon, a chlorinated hydrocarbon is more preferable, for example, a dichloromethane, chloroform, etc. are mentioned, A dichloromethane is further more preferable.
Examples of the ester include methyl formate, ethyl formate, methyl acetate, and ethyl acetate.
Examples of the ketone include acetone and methyl ethyl ketone.
Examples of the ether include diethyl ether, methyl tert-butyl ether, diisopropyl ether, dimethoxymethane, 1,3-dioxolane, 4-methyldioxolane, tetrahydrofuran, methyltetrahydrofuran, 1,4-dioxane and the like.
As said alcohol, methanol, ethanol, 2-propanol etc. are mentioned, for example.
Examples of the hydrocarbon include n-pentane, cyclohexane, n-hexane, benzene, toluene and the like.

  Examples of the organic solvent used in combination with these main solvents include halogenated hydrocarbons, esters, ketones, ethers, alcohols and hydrocarbons, which may have a branched structure or a cyclic structure. The organic solvent may have any two or more of ester, ketone, ether and alcohol functional groups (that is, —O—, —CO—, —COO—, —OH). Furthermore, the hydrogen atom in the hydrocarbon portion of the ester, ketone, ether and alcohol may be substituted with a halogen atom (particularly a fluorine atom).

Preferred examples of the organic solvent used in combination with the main solvent include the following examples in addition to the examples given as the organic solvent used in the main solvent.
Examples of the ester include propyl formate, pentyl formate, and pentyl acetate.
Examples of the ketone include diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone.
Examples of the ether include dimethoxyethane, anisole, phenetole and the like.
Examples of the alcohol include 1-propanol, 1-butanol, 2-butanol, tert-butanol, 1-pentanol, 2-methyl-2-butanol, cyclohexanol, 2-fluoroethanol, 2,2,2-trifluoro. Examples include ethanol, 2,2,3,3-tetrafluoro-1-propanol, and the like. Preferred is an alcohol having 1 to 4 carbon atoms, more preferred is methanol, ethanol or butanol, and most preferred is methanol or butanol.
Examples of the hydrocarbon include xylene.
Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol, 2-butoxyethanol, and methyl acetoacetate.

Since the cellulose acylate contained in the dope contains a hydrogen bonding functional group such as a hydroxyl group, an ester or a ketone, it is 5 to 30% by mass in the total solvent, more preferably 7 to 25% by mass, and still more preferably. It is preferable from a viewpoint of the peeling load reduction from a casting support body to contain 10-20 mass% alcohol.
By adjusting the alcohol content, it is possible to easily adjust the expression of Re and Rth of the cellulose acylate film produced by the production method of the present invention.
Further, in the present invention, it is effective to contain a small amount of water to increase the solution viscosity and the film strength in the wet film state at the time of drying, or to increase the dope strength at the time of casting the drum method. It may be contained in an amount of 0.1 to 5% by mass, more preferably 0.1 to 3% by mass, and particularly 0.2 to 2% by mass.

  Examples of combinations of organic solvents preferably used as the solvent for the dope are the same as those described in JP-A 2009-262551 (1) to (31), but the present invention is not limited thereto. In addition, the numerical value of a ratio means a mass part.

  In addition, if necessary, a non-halogen organic solvent can be used as a main solvent, and detailed description can be found in the Japan Institute of Invention Publication (Publication No. 2001-1745, published on March 15, 2001, Invention Association). There is a description.

Cellulose acylate:
In the present invention, cellulose acylate is used as the main component of the film. Here, in the present specification, the “main component” refers to a component having a highest mass fraction in an embodiment in which there is one component as a raw material and in an embodiment having two or more components. One type of cellulose acylate may be used, or two or more types may be used. The acyl substituent of cellulose acylate may be, for example, a cellulose acylate composed of an acetyl group alone, or a plurality of acyl substituents. You may use the composition containing the cellulose acylate which has this.

Cellulose ester is an ester of cellulose and acid. As the acid constituting the ester, an organic acid is preferable, a carboxylic acid is more preferable, a fatty acid having 2 to 22 carbon atoms is further preferable, and a lower fatty acid having 2 to 4 carbon atoms is most preferable.
The cellulose acylate is an ester of cellulose and carboxylic acid. In the cellulose acylate, all or part of the hydrogen atoms of the hydroxyl groups present at the 2-position, 3-position and 6-position of the glucose unit constituting the cellulose are substituted with acyl groups. Examples of the acyl group include, for example, acetyl group, propionyl group, butyryl group, isobutyryl group, pivaloyl group, heptanoyl group, hexanoyl group, octanoyl group, decanoyl group, dodecanoyl group, tridecanoyl group, tetradecanoyl group, hexadecanoyl group, and hexadecanoyl group. Examples include noyl group, octadecanoyl group, cyclohexanecarbonyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, and cinnamoyl group. As the acyl group, acetyl group, propionyl group, butyryl group, dodecanoyl group, octadecanoyl group, pivaloyl group, oleoyl group, benzoyl group, naphthylcarbonyl group, cinnamoyl group are preferable, acetyl group, propionyl group, butyryl group Is most preferred.
The cellulose ester may be an ester of cellulose and a plurality of acids. Cellulose acylate may be substituted with a plurality of acyl groups.

When the substitution degree of the acetyl group (carbon number 2) substituted on the hydroxyl group of cellulose of cellulose acylate is SA and the substitution degree of the acyl group of 3 or more carbon atoms substituted on the hydroxyl group of cellulose is SB, By adjusting SA and SB, the reproducibility of the cellulose acylate film produced by the production method of the present invention and the humidity dependence of the retardation can be adjusted. The humidity dependency of retardation is a reversible change in retardation due to humidity.
SA + SB is appropriately adjusted depending on the optical properties required for the cellulose acylate film, but preferably 2.70 ≦ SA + SB ≦ 3.00, more preferably 2.80 ≦ SA + SB ≦ 2.97, and even more preferably. Is 2.83 ≦ SA + SB ≦ 2.89.
Moreover, the humidity dependence of the retardation of the cellulose acylate film produced by the production method of the present invention can be adjusted by adjusting SB. By increasing SB, the humidity dependency of retardation can be reduced and the melting point is lowered. In consideration of the humidity dependence of the retardation and the balance of the melting point, the range of SB is preferably 0 <SB ≦ 3.0, more preferably 0 <SB ≦ 1.0, and particularly preferably SB = 0. When all the hydroxyl groups of cellulose are substituted, the degree of substitution is 3.

Cellulose acylate can be synthesized by a known method.
For example, the basic principle of the cellulose acylate synthesis method is described in Nobuhiko Umeda et al., Wood Chemistry, 180-190 (Kyoritsu Shuppan, 1968). A typical synthesis method of cellulose acylate includes a liquid phase acylation method using a carboxylic acid anhydride-carboxylic acid-sulfuric acid catalyst. Specifically, first, cellulose raw materials such as cotton linter and wood pulp are pretreated with a suitable amount of carboxylic acid such as acetic acid, and then esterified by introducing into a pre-cooled acylated mixture to complete cellulose acylate (2 The total degree of acyl substitution at the 3rd, 6th and 6th positions is approximately 3.00). The acylated mixed solution generally contains a carboxylic acid as a solvent, a carboxylic acid anhydride as an esterifying agent, and sulfuric acid as a catalyst. In addition, the carboxylic acid anhydride is usually used in a stoichiometrically excessive amount with respect to the total amount of cellulose reacting with the carboxylic acid anhydride and moisture present in the system.

  Subsequently, after completion of the acylation reaction, water or hydrous acetic acid is added in order to hydrolyze the excess carboxylic anhydride remaining in the system. Further, in order to partially neutralize the esterification catalyst, an aqueous solution containing a neutralizing agent (for example, calcium, magnesium, iron, aluminum or zinc carbonate, acetate, hydroxide or oxide) is added. Also good. Furthermore, the obtained complete cellulose acylate is saponified and aged by maintaining it at 20 to 90 ° C. in the presence of a small amount of acylation reaction catalyst (generally, remaining sulfuric acid) to obtain the desired degree of acyl substitution and degree of polymerization. Change to cellulose acylate. When the desired cellulose acylate is obtained, the catalyst remaining in the system is completely neutralized using the neutralizing agent or the like, or water or dilute without neutralizing the catalyst. Cellulose acylate can be obtained by introducing a polymer solution into acetic acid (or adding water or dilute acetic acid into the polymer solution) to separate cellulose acylate, and washing and stabilizing treatment.

  The degree of polymerization of the cellulose acylate is preferably from 150 to 500, more preferably from 200 to 400, and even more preferably from 220 to 350 in terms of viscosity average degree of polymerization. The viscosity average degree of polymerization can be measured according to the description of Uda et al.'S intrinsic viscosity method (Kazuo Uda, Hideo Saito, Journal of Textile Science, Vol. 18, No. 1, pages 105-120, 1962). The method for measuring the viscosity average degree of polymerization is also described in JP-A-9-95538.

In addition, cellulose acylate having a small amount of low molecular components has a high average molecular weight (degree of polymerization), but its viscosity is lower than that of ordinary cellulose acylate. Such a cellulose acylate having a small amount of low molecular components can be obtained by removing the low molecular components from cellulose acylate synthesized by an ordinary method. The removal of the low molecular components can be performed by washing the cellulose acylate with an appropriate organic solvent. In addition, cellulose acylate having a small amount of low molecular components can be obtained by synthesis. When synthesizing cellulose acylate having a small amount of low molecular components, the amount of sulfuric acid catalyst in the acylation reaction is preferably adjusted to 0.5 to 25 parts by mass with respect to 100 parts by mass of cellulose. When the amount of the sulfuric acid catalyst is within the above range, cellulose acylate that is preferable in terms of molecular weight distribution (uniform molecular weight distribution) can be synthesized. The degree of polymerization and molecular weight distribution of cellulose acylate can be measured by gel permeation chromatography (GPC) or the like.
The raw material cotton of cellulose ester and the synthesis method are also described in pages 7 to 12 of the Japan Society of Invention Disclosure (Public Technical Number 2001-1745, published on March 15, 2001, Japan Society of Invention).

  As a cellulose acylate used as a raw material when producing a cellulose acylate film, a powder or a particulate material can be used, and a pelletized one can also be used. The water content of cellulose acylate when used as a raw material is preferably 1.0% by mass or less, more preferably 0.7% by mass or less, and most preferably 0.5% by mass or less. . Moreover, it is preferable that the said moisture content is 0.2 mass% or less depending on the case. When the water content of the cellulose acylate is not within the preferred range, it is preferable to use the cellulose acylate after drying it by drying air or heating.

Aromatic group-containing oligomer:
In the present invention, an aromatic group-containing oligomer is used as a plasticizer. The plasticizer is an essential material for accelerating the volatilization rate of the solvent and reducing the residual solvent amount. In order to act as a plasticizer, the number average molecular weight of the oligomer is preferably 500 to 2000, and more preferably 500 to 1500. In terms of oligomer crying and web handling, the oligomer is preferably 20 parts by mass or less, more preferably 15 parts by mass or less with respect to 100 parts by mass of the cellulose acylate. . On the other hand, from the viewpoint of web drying speed, the oligomer is preferably 3 parts by mass or more, and more preferably 5 parts by mass or more with respect to 100 parts by mass of the cellulose acylate.
In addition, an aromatic group containing oligomer may be only 1 type, or may use 2 or more types.

  The aromatic group-containing oligomer may be liquid or solid under the ambient temperature or humidity used (generally room temperature conditions, so-called 25 ° C., relative humidity 60%). Further, the smaller the color, the better, and it is particularly preferable that the color is colorless. It is preferably thermally stable at a higher temperature, and the decomposition start temperature is 150 ° C. or higher, more preferably 200 ° C. or higher, and more preferably 250 ° C. or higher.

One feature of the aromatic group-containing oligomer that can be used in the present invention is that it contains an aromatic group. By regularly including an aromatic group in a part of the repeating unit in the oligomer, the degree of molecular orientation of the oligomer after the heat treatment can be effectively increased. The aromatic group-containing oligomer is preferably a polycondensed ester containing at least one dicarboxylic acid residue and at least one diol residue. The aromatic group may be contained in the dicarboxylic acid residue or may be contained in the diol residue, and among them, a polycondensed ester containing the aromatic group in the dicarboxylic acid residue is preferable. More specifically, the aromatic group-containing oligomer is preferably selected from polycondensation esters containing at least one aromatic dicarboxylic acid residue and at least one aliphatic diol residue.
Hereinafter, the polycondensation ester plasticizer that can be used as an aromatic group-containing oligomer in the present invention will be described in detail.

Polycondensed ester:
In the present invention, it is preferable to use a polycondensed ester obtained by the reaction of an aromatic dicarboxylic acid and an aliphatic glycol as the aromatic group-containing oligomer. Although both ends of the reaction product may remain as the reaction product, so-called end-capping may be carried out by further reacting monocarboxylic acid or monoalcohol. It is effective in terms of preservability that the end capping is performed particularly in order not to contain a free carboxylic acid. The dicarboxylic acid used in the polycondensed ester is preferably an aromatic dicarboxylic acid, more preferably an aromatic dicarboxylic acid having 8 to 12 carbon atoms. The glycol used in the polycondensed ester is preferably an aliphatic glycol, and is preferably an aliphatic glycol having 2 to 12 carbon atoms. Aliphatic glycols also include alicyclic glycols.

Examples of the aromatic dicarboxylic acid having 8 to 12 carbon atoms include phthalic acid, terephthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid and the like. Among these, terephthalic acid is preferable because of its high Re developability. These are each used as a mixture of one or more.
The polycondensed ester may contain an aliphatic dicarboxylic acid residue. Examples of the aliphatic dicarboxylic acid residue include an aliphatic dicarboxylic acid residue having 4 to 12 carbon atoms. Examples of the alkylene dicarboxylic acid having 4 to 12 carbon atoms include succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and the like. .

  Examples of aliphatic glycols having 2 to 12 carbon atoms include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1 , 3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3-methyl-1,5-pentanediol, 1,6- Hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2-methyl-1,8-oct Njioru, 1,9-nonanediol, 1,10-decanediol, 1,12 has octadecanediol etc., these glycols may be used alone or in combination.

  In addition, it is preferable to protect the polycondensed ester with a monoalcohol residue or a monocarboxylic acid residue so that both ends of the polycondensed ester are not carboxylic acid. In that case, as a preferable aspect as a monoalcohol residue, the aspect described in Unexamined-Japanese-Patent No. 2009-262551 can be mentioned, for example.

  Examples of monocarboxylic acids that can be used for sealing include substituted or unsubstituted monocarboxylic acids having 1 to 30 carbon atoms. These may be aliphatic monocarboxylic acids or aromatic carboxylic acids. First, preferred aliphatic monocarboxylic acids will be described. Examples include acetic acid, propionic acid, butanoic acid, caprylic acid, caproic acid, decanoic acid, dodecanoic acid, stearic acid, and oleic acid. Preferred examples of the aromatic monocarboxylic acid include Examples thereof include, for example, embodiments described in JP-A-2009-262551, and these can be used as a single type or a mixture of two or more types.

  As described above, specific examples of the method for synthesizing the polycondensed ester and commercial products include the modes described in JP-A-2009-262551.

Although the specific example of the said polycondensation ester which can be utilized for this invention is described below, it is not limited to the following specific examples.
PP-1: Condensate with ethanediol / terephthalic acid (1/1 molar ratio) (number average molecular weight 1000)
PP-2: Condensate with 1,2 propanediol / terephthalic acid (1/1 molar ratio) (number average molecular weight 1000)
PP-3: Condensate (number average molecular weight 1000) with ethanediol / 1,2 propanediol / terephthalic acid (0.5 / 0.5 / 1 molar ratio)
PP-4: Condensate (number average molecular weight 1000) with ethanediol / 1,2 propanediol / terephthalic acid / succinic acid (0.5 / 0.5 / 0.7 / 0.3 molar ratio)
PP-5: Condensate (number average molecular weight 1000) with ethanediol / 1,2 propanediol / terephthalic acid / succinic acid (0.5 / 0.5 / 0.55 / 0.45 molar ratio)
PP-6: Ethyldiol / 1,2 propanediol / terephthalic acid / succinic acid (0.5 / 0.5 / 0.7 / 0.3 molar ratio) octyl esterified product (number average) at the terminal of the condensate Molecular weight 1000)
PP-7: Condensate with 1,3-propanediol / 1,5-naphthalenedicarboxylic acid (1/1 molar ratio) (number average molecular weight 1500)
PP-8: Condensation product with 2-methyl-1,3-propanediol / isophthalic acid (1/1 molar ratio) (number average molecular weight 1200)
PP-9: Condensate with 1,3-propanediol / terephthalic acid (1/1 molar ratio) benzyl esterified compound at both ends (number average molecular weight 1500)
PP-10: 1,3-propanediol / 1,5-naphthalenedicarboxylic acid condensate with propyl esterified product (1/1 molar ratio) at both ends (number average molecular weight 1500)
PP-11: Condensation product of 2-methyl-1,3-propanediol / isophthalic acid (1/1 molar ratio) at both ends butyl esterified product (number average molecular weight 1200)

Wavelength dispersion adjusting agent:
A chromatic dispersion adjusting agent may be added to the dope used in the method of the present invention for the purpose of adjusting chromatic dispersion.

  The wavelength dispersion adjusting agent is a compound having an absorption maximum in a wavelength range of 250 to 400 nm, preferably 300 to 400 nm, and more preferably 360 to 400 nm. By adding such a wavelength dispersion adjusting agent, a film satisfying the wavelength dispersion condition of the present invention can be easily produced. The wavelength dispersion adjusting agent may be a compound having an absorption maximum in a wavelength range of 250 to 400 nm, and may be a compound that absorbs light in a wavelength range other than 250 to 400 nm.

  The wavelength dispersion adjusting agent used in the present invention is preferably a compound that is substantially free from volatilization in all processes for producing an optical compensation film and a liquid crystal display device. The wavelength dispersion adjusting agent may be used alone or in combination of two or more. The total addition amount of the wavelength dispersion adjusting agent varies depending on the optical properties and the like imparted to the film, but is preferably 0.2 to 20% by mass, more preferably 0.2 to 10% by mass, and still more preferably. Is 0.5-5 mass%. The wavelength dispersion adjusting agent is preferably added and mixed in advance with a film-forming melt or solution before film formation.

  The wavelength dispersion adjusting agent used in the present invention is preferably a compound represented by any one of the following general formulas (I) to (VIII). Among the following general formulas (I) to (VIII), compounds represented by the general formula (I) are more preferable.

R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ^{17 in the} above general formula (I); R ²¹ , R ²² , R ²³ , R ²⁴ , R ^{25 in the} above general formula (II) , R ²⁶ , R ²⁷ , R ²⁸ , and R ²⁹ ; R ⁴¹ , R ⁴² , R ⁴³ , R ⁴⁴ , R ⁴⁵ , R ⁴⁶ , and R ^{47 in the} above general formula (III); in the above general formula (IV) R ⁵¹ , R ⁵² , R ⁵³ , R ⁵⁴ , R ⁵⁵ , R ⁵⁶ , and R ⁵⁷ ; R ⁶¹ , R ⁶² , R ⁶³ , R ⁶⁴ , R ⁶⁵ , R ⁶⁶ , R ⁶⁷ in the general formula (V) And R ⁶⁸ ; R ⁷¹ , R ⁷² , R ⁷³ , R ⁷⁴ , R ⁷⁵ and R ^{76 in the} general formula (VI); R ⁸¹ , R ⁸² , R ⁸³ , R ⁸⁴ and R ⁸⁵ in the general formula (VII) In the general formula (VIII), R ⁸⁶ , R ⁸⁷ and R ⁸⁸ each independently represents a hydrogen atom or a substituent.
In the general formulas (I) to (VIII), it is preferable to combine the substituents so that the horizontal direction (left-right direction) of the paper surface is the molecular major axis direction.

As the substituent, preferably,
A halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (preferably an alkyl group having 1 to 30 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms, such as a methyl group, an ethyl group, n-propyl group, isopropyl group, tert-butyl group, n-octyl group, 2-ethylhexyl group), cycloalkyl group (preferably having 3 to 30 carbon atoms, more preferably having 3 to 10 carbon atoms) A substituted cycloalkyl group, for example, a cyclohexyl group, a cyclopentyl group, a 4-n-dodecylcyclohexyl group), a bicycloalkyl group (preferably 5-30 carbon atoms, more preferably 5-10 carbon atoms substituted or unsubstituted) A bicycloalkyl group, that is, preferably a bicycloa having 5 to 30 carbon atoms, more preferably 5 to 10 carbon atoms. A monovalent group obtained by removing one hydrogen atom from a lukane, for example, bicyclo [1.2.2] heptan-2-yl, bicyclo [2.2.2] octane-3-yl), an alkenyl group (preferably Is a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, more preferably 2 to 10 carbon atoms, such as a vinyl group or an allyl group, or a cycloalkenyl group (preferably having 3 to 30 carbon atoms, more preferably Is a monovalent or cycloalkyl group having 3 to 10 carbon atoms, ie, a monovalent alkenyl group in which one hydrogen atom of a cycloalkene having 3 to 30 carbon atoms, more preferably 3 to 10 carbon atoms is removed. For example, 2-cyclopenten-1-yl, 2-cyclohexen-1-yl), bicycloalkenyl group (substituted or unsubstituted bicycloalkenyl group, preferably Is a substituted or unsubstituted bicycloalkenyl group having 5 to 30 carbon atoms, more preferably 5 to 10 carbon atoms, that is, a monovalent group in which one hydrogen atom of a bicycloalkene having one double bond is removed. For example, bicyclo [2.2.1] hept-2-en-1-yl, bicyclo [2.2.2] oct-2-en-4-yl), an alkynyl group (preferably having 2 to 30 carbon atoms) More preferably a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, such as an ethynyl group or a propargyl group, an aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 10 carbon atoms). A substituted or unsubstituted aryl group such as a phenyl group, a p-tolyl group, a naphthyl group), a heterocyclic group (preferably a 5- or 6-membered substituted or unsubstituted aromatic or non-aromatic heterocyclic group A monovalent group obtained by removing one hydrogen atom from an object, more preferably 3 to 30 carbon atoms, more preferably a heterocyclic group having an aromatic 5- or 6-membered 3-10 carbon atoms. For example, 2-furyl group, 2-thienyl group, 2-pyrimidinyl group, 2-benzothiazolyl group), cyano group, hydroxyl group, nitro group, carboxyl group, alkoxy group (preferably having 1 to 30 carbon atoms, more preferably C1-C10 substituted or unsubstituted alkoxy groups such as methoxy, ethoxy, isopropoxy, tert-butoxy, n-octyloxy, 2-methoxyethoxy), aryloxy (preferably Is a substituted or unsubstituted aryloxy group having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms, such as phenoxy group, 2-methylphenoxy group, 4-tert-butylphenoxy group, 3-nitrophenoxy group. Group, 2-tetradecanoylaminophenoxy group), silyloxy group (preferably having 3 to 20 carbon atoms, more Preferably, it is a silyloxy group having 3 to 10 carbon atoms, such as trimethylsilyloxy group or tert-butyldimethylsilyloxy group, a heterocyclic oxy group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 2 carbon atoms). 10 substituted or unsubstituted heterocyclic oxy groups, 1-phenyltetrazole-5-oxy group, 2-tetrahydropyranyloxy group), acyloxy group (preferably formyloxy group, 2-30 carbon atoms, more preferably A substituted or unsubstituted alkylcarbonyloxy group having 2 to 10 carbon atoms, 6 to 30 carbon atoms, more preferably a substituted or unsubstituted arylcarbonyloxy group having 6 to 10 carbon atoms, such as a formyloxy group, Acetyloxy group, pivaloyloxy group, stearoyloxy group, benzoyloxy group, p-methoxy Phenylcarbonyloxy group), a carbamoyloxy group (preferably a substituted or unsubstituted carbamoyloxy group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, such as an N, N-dimethylcarbamoyloxy group, N , N-diethylcarbamoyloxy group, morpholinocarbonyloxy group, N, N-di-n-octylaminocarbonyloxy group, Nn-octylcarbamoyloxy group), alkoxycarbonyloxy group (preferably having 2 to 30 carbon atoms) More preferably a substituted or unsubstituted alkoxycarbonyloxy group having 2 to 10 carbon atoms, for example, a methoxycarbonyloxy group, an ethoxycarbonyloxy group, a tert-butoxycarbonyloxy group, an n-octylcarbonyloxy group), an aryloxycarbonyloxy Group (preferably A substituted or unsubstituted aryloxycarbonyloxy group having 7 to 30 carbon atoms, more preferably 7 to 10 carbon atoms, for example, phenoxycarbonyloxy group, p-methoxyphenoxycarbonyloxy group, pn-hexadecyl Oxyphenoxycarbonyloxy group), amino group (preferably an amino group, 1-30 carbon atoms, more preferably a substituted or unsubstituted alkylamino group having 1-10 carbon atoms, 6-30 carbon atoms, and more. Preferably a substituted or unsubstituted anilino group having 6 to 10 carbon atoms, for example, an amino group, a methylamino group, a dimethylamino group, an anilino group, an N-methyl-anilino group, a diphenylamino group), an acylamino group (preferably A formylamino group, substituted or unsubstituted 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms Substituted alkylcarbonylamino group, substituted or unsubstituted arylcarbonylamino group having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms, such as formylamino group, acetylamino group, pivaloylamino group, lauroylamino group A benzoylamino group), an aminocarbonylamino group (preferably a substituted or unsubstituted aminocarbonylamino group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, such as a carbamoylamino group, N, N -Dimethylaminocarbonylamino group, N, N-diethylaminocarbonylamino group, morpholinocarbonylamino group), alkoxycarbonylamino group (preferably having 2 to 30 carbon atoms, more preferably having 2 to 10 carbon atoms) An alkoxycarbonylamino group such as Xoxycarbonylamino group, ethoxycarbonylamino group, tert-butoxycarbonylamino group, n-octadecyloxycarbonylamino group, N-methyl-methoxycarbonylamino group), aryloxycarbonylamino group (preferably having 7 to 30 carbon atoms) More preferably a substituted or unsubstituted aryloxycarbonylamino group having 7 to 10 carbon atoms, such as phenoxycarbonylamino group, p-chlorophenoxycarbonylamino group, mn-octyloxyphenoxycarbonylamino group), Famoylamino group (preferably a substituted or unsubstituted sulfamoylamino group having 0 to 30 carbon atoms, more preferably 0 to 10 carbon atoms, such as sulfamoylamino group, N, N-dimethylamino Sulfonylamino group, Nn-o Tilaminosulfonylamino group), alkyl and arylsulfonylamino groups (preferably having 1 to 30 carbon atoms, more preferably substituted or unsubstituted alkylsulfonylamino having 1 to 10 carbon atoms, 6 to 30 carbon atoms, and more) Preferably, the substituted or unsubstituted arylsulfonylamino group having 6 to 10 carbon atoms, for example, methylsulfonylamino group, butylsulfonylamino group, phenylsulfonylamino group, 2,3,5-trichlorophenylsulfonylamino group, p- Methylphenylsulfonylamino group),

Mercapto group, alkylthio group (preferably a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, for example, methylthio group, ethylthio group, n-hexadecylthio group), arylthio group ( Preferably a substituted or unsubstituted arylthio group having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms, such as phenylthio group, p-chlorophenylthio group, m-methoxyphenylthio group), heterocyclic thio group (Preferably a substituted or unsubstituted heterocyclic thio group having 2 to 30 carbon atoms, more preferably 2 to 10 carbon atoms, for example, 2-benzothiazolylthio group, 1-phenyltetrazol-5-ylthio group) A sulfamoyl group (preferably substituted or unsubstituted having 0 to 30 carbon atoms, more preferably 0 to 10 carbon atoms) Sulfamoyl groups such as N-ethylsulfamoyl group, N- (3-dodecyloxypropyl) sulfamoyl group, N, N-dimethylsulfamoyl group, N-acetylsulfamoyl group, N-benzoylsulfamoyl Group, N- (N′phenylcarbamoyl) sulfamoyl group), sulfo group, alkyl and arylsulfinyl group (preferably substituted or unsubstituted alkylsulfinyl having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms) A substituted or unsubstituted arylsulfinyl group having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms, more preferably 6 to 10 carbon atoms, such as a methylsulfinyl group, an ethylsulfinyl group, a phenylsulfinyl group, p -Methylphenylsulfinyl group), alkyl and arylsulfur Nyl group (preferably a substituted or unsubstituted alkylsulfonyl group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, and a substituted group having 6 to 30 carbon atoms, more preferably 6 to 10 carbon atoms. Or an unsubstituted arylsulfonyl group such as a methylsulfonyl group, an ethylsulfonyl group, a phenylsulfonyl group, a p-methylphenylsulfonyl group), an acyl group (preferably a formyl group, 2 to 30 carbon atoms, more preferably a carbon atom) A substituted or unsubstituted alkylcarbonyl group having 2 to 10 carbon atoms, 7 to 30 carbon atoms, more preferably a substituted or unsubstituted arylcarbonyl group having 7 to 10 carbon atoms, such as an acetyl group and a pivaloylbenzoyl group ), An aryloxycarbonyl group (preferably having 7 to 30 carbon atoms, more preferably 7 to 10 carbon atoms). A substituted or unsubstituted aryloxycarbonyl group, for example, phenoxycarbonyl group, o-chlorophenoxycarbonyl group, m-nitrophenoxycarbonyl group, p-tert-butylphenoxycarbonyl group), alkoxycarbonyl group (preferably having a carbon atom number) 2-30, more preferably a substituted or unsubstituted alkoxycarbonyl group having 2 to 10 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a tert-butoxycarbonyl group, an n-octadecyloxycarbonyl group), a carbamoyl group (preferably Is a substituted or unsubstituted carbamoyl group having 1 to 30 carbon atoms, more preferably 1 to 10 carbon atoms, such as a carbamoyl group, N-methylcarbamoyl group, N, N-dimethylcarbamoyl group, N, N— Di-n-octylcarbamoyl group, N (Methylsulfonyl) carbamoyl group), aryl and heterocyclic azo groups (preferably 6-30 carbon atoms, more preferably 6-10 carbon atoms substituted or unsubstituted arylazo groups, 3-30 carbon atoms, more Preferably a substituted or unsubstituted heterocyclic azo group having 3 to 10 carbon atoms, for example, phenylazo group, p-chlorophenylazo group, 5-ethylthio-1,3,4-thiadiazol-2-ylazo group), imide group (Preferably N-succinimide group, N-phthalimide group), phosphino group (preferably a substituted or unsubstituted phosphino group having 2 to 30 carbon atoms, more preferably 2 to 10 carbon atoms, for example, dimethylphosphino Group, diphenylphosphino group, methylphenoxyphosphino group), phosphinyl group (preferably having 2 to 3 carbon atoms) More preferably a substituted or unsubstituted phosphinyl group having 2 to 10 carbon atoms, such as a phosphinyl group, a dioctyloxyphosphinyl group, a diethoxyphosphinyl group, or a phosphinyloxy group (preferably a carbon atom) A substituted or unsubstituted phosphinyloxy group having 2 to 30 carbon atoms, more preferably 2 to 10 carbon atoms, such as a diphenoxyphosphinyloxy group or a dioctyloxyphosphinyloxy group), a phosphinylamino group (Preferably a substituted or unsubstituted phosphinylamino group having 2 to 30 carbon atoms, more preferably 2 to 10 carbon atoms, such as a dimethoxyphosphinylamino group or a dimethylaminophosphinylamino group) A silyl group (preferably a substituted or unsubstituted silyl group having 3 to 30 carbon atoms, more preferably 3 to 10 carbon atoms, For example, trimethylsilyl group, tert-butyldimethylsilyl group, phenyldimethylsilyl group).

  Among the above substituents, those having a hydrogen atom may be substituted with the above groups after removing this. Examples of such functional groups include an alkylcarbonylaminosulfonyl group, an arylcarbonylaminosulfonyl group, an alkylsulfonylaminocarbonyl group, and an arylsulfonylaminocarbonyl group. Examples thereof include a methylsulfonylaminocarbonyl group, a p-methylphenylsulfonylaminocarbonyl group, an acetylaminosulfonyl group, and a benzoylaminosulfonyl group.

Among the above substituents, more preferable are a halogen atom, an alkyl group, an aryl group, an alkoxy group, a cyano group, a hydroxyl group, a carboxyl group, and an arylsulfonyl group, and more preferable are an alkyl group, an alkoxy group, A hydroxyl group, a carboxyl group, and a phenylsulfonyl group;
Moreover, when there are two or more substituents in one molecule, these substituents may be the same or different. Further, if possible, they may be linked to each other to form a ring (including a condensed ring with a ring described in the general formula).

  The molecular weight of the wavelength dispersion adjusting agent used in the present invention is preferably 100 to 5000, more preferably 150 to 3000, and further preferably 200 to 2000.

(Merocyanine compounds)
Examples of the wavelength dispersion adjusting agent used in the present invention include merocyanine compounds represented by the following general formula (IX). Among the merocyanine compounds, it is preferable to use a compound having a λmax satisfying 370 nm ≦ λmax ≦ 400 nm.

In the general formula (IX), N represents a nitrogen atom; R ^{1 to} R ⁷ each represents a hydrogen atom or a substituent. In the general formula (IX), it is preferable to combine the substituents so that the horizontal direction (left-right direction) of the paper surface is the molecular major axis direction.

Examples of the substituent represented by each of R ^{1 to} R ⁷ are the same as the examples of the substituent represented by R ^{11 and the} like in the general formula (I).

In the general formula (IX), R ¹ and R ² each represents a substituted or unsubstituted alkyl group, and R ¹ and R ² may be bonded to each other to form a ring containing a nitrogen atom; R ⁶ and R ⁷ each represent a substituent having Hammett's substituent constant σp value of 0.2 or more, or R ⁶ and R ⁷ may be bonded to each other to form a cyclic active methylene compound structure. Well; preferably R ³ , R ⁴ and R ⁵ each represent a hydrogen atom.

The alkyl group represented by each of R ¹ and R ² is preferably an alkyl group having 1 to 20 carbon atoms (preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms), such as a methyl group, an ethyl group, A propyl group etc. are mentioned. The alkyl group may be linear or branched. You may have a substituent in the arbitrary positions on an alkyl group. Examples of the substituent include a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom), aryl group (eg, phenyl, naphthyl), cyano group, carboxyl group, alkoxycarbonyl group (eg, methoxycarbonyl), aryloxy Carbonyl group (for example, phenoxycarbonyl), substituted or unsubstituted carbamoyl group (for example, carbamoyl, N-phenylcarbamoyl, N, N-dimethylcarbamoyl), alkylcarbonyl group (for example, acetyl), arylcarbonyl group (for example, benzoyl), nitro group Substituted or unsubstituted amino groups (eg amino, dimethylamino, anilino), acylamino groups (eg acetamido, ethoxycarbonylamino), sulfonamido groups (eg methanesulfonamido), imide groups (eg supra) Synimide, phthalimide), imino group (eg benzylideneamino), hydroxy group, alkoxy group (eg methoxy), aryloxy group (eg phenoxy), acyloxy group (eg acetoxy), alkylsulfonyloxy group (eg methanesulfonyloxy), aryl A sulfonyloxy group (for example, benzenesulfonyloxy), a sulfo group, a substituted or unsubstituted sulfamoyl group (for example, sulfamoyl, N-phenylsulfamoyl), an alkylthio group (for example, methylthio), an arylthio group (for example, phenylthio), an alkylsulfonyl group ( Examples thereof include methanesulfonyl), arylsulfonyl groups (for example, benzenesulfonyl), and heterocyclic groups (for example, pyridyl, morpholino). Moreover, the substituent may be further substituted, and when there are a plurality of substituents, they may be the same or different. Moreover, you may combine with substituents and may form a ring.

R ¹ and R ² may be bonded to each other to form a ring containing a nitrogen atom. The ring is preferably a saturated ring, preferably a saturated 6-membered ring, and more preferably a piperidine ring.

R ¹ and R ² are preferably an unsubstituted alkyl group, an alkyl group substituted with a cyano group, an alkoxycarbonyl group or a phenyl group, or bonded to each other to form a piperidine ring.

R ⁶ and R ⁷ each represent a substituent having a Hammett's substituent constant σp value of 0.2 or more, and R ⁶ and R ⁷ may be bonded to each other to form a ring. Hammett's substituent constant σ value will be described. Hammett's rule is a method described in 1935 by L. E. in order to quantitatively discuss the effect of substituents on the reaction or equilibrium of benzene derivatives. P. A rule of thumb proposed by Hammett, which is widely accepted today. Substituent constants determined by Hammett's rule include σp value and σm value, and these values can be found in many general books. For example, J. et al. A. Dean, “Lange's Handbook of Chemistry”, 12th edition, 1979 (Mc Graw-Hill) and “Areas of Chemistry”, No. 122, 96-103, 1979 (Nankodo), Chem. Rev. 1991, 91, 165-195. The substituent having Hammett's substituent constant σp value of 0.2 or more in the present invention is an electron-attracting group. The σp value is preferably 0.25 or more, more preferably 0.3 or more, and particularly preferably 0.35 or more.

Examples of R ⁶ and R ⁷ include a cyano group (0.66), a carboxyl group (—COOH: 0.45), an alkoxycarbonyl group (—COOMe: 0.45), an aryloxycarbonyl group (—COOPh: 0). .44), a carbamoyl group (—CONH ₂ : 0.36), an alkylcarbonyl group (—COMe: 0.50), an arylcarbonyl group (—COPh: 0.43), an alkylsulfonyl group (—SO ₂ Me: 0) .72) or an arylsulfonyl group (—SO ₂ Ph: 0.68). In the present specification, Me represents a methyl group, and Ph represents a phenyl group. The values in parentheses are the σp values of typical substituents in Chem. Rev. 1991, Vol. 91, pp. 165-195.

R ⁶ and R ⁷ may be bonded to each other, and R ⁶ and R ⁷ may be bonded to each other to form a cyclic active methylene compound structure. The “active methylene compound” means a series of compounds having a methylene group (—CH ₂ —) sandwiched between two electron withdrawing groups. The carbon atom to which R ⁶ and R ⁷ are bonded is preferably active methylene.

  Among the merocyanine compounds, merocyanine compounds represented by the following general formula (IXa) are preferable.

In the general formula (IXa), R ¹¹ and R ¹² each represent an alkyl group, an aryl group, a cyano group, or —COOR ¹³ , or are bonded to each other to form a ring containing a nitrogen atom; R ⁶ and R each ^7, - cyano group, -COOR ^14, or represents a -SO ₂ R ^15, bonded to each other, forming one of the annular active methylene following structure (IXa-1) ~ (IXa -6) R ¹³ , R ^14, and R ¹⁵ each represents an alkyl group, an aryl group, or a heterocyclic group.

In the active methylene structures (IXa-1) to (IXa-6), “**” represents the bonding position with the general formula (IXa); R ^a and R ^b are each a hydrogen atom or C _{1 to} C ₂₀ (preferably C _{1 to} C ₂₀ , more preferably C _{1 to} C ₅ ) represents an alkyl group; X represents an oxygen atom or a sulfur atom.

The alkyl group represented by each of R ¹¹ and R ¹² may be unsubstituted or may have a substituent. Examples of the substituents, R ¹ and R ² are the same as the examples of the substituents represented respectively. The alkyl group preferably has 1 to 20 carbon atoms, preferably 1 to 15 and more preferably 1 to 6.
The aryl group represented by each of R ¹¹ and R ¹² may be unsubstituted or may have a substituent. Examples of the substituents, R ¹ and R ² are the same as the examples of the substituents represented respectively. The aryl group is preferably a phenyl group, and more preferably an unsubstituted phenyl group.
In —COOR ¹³ represented by each of R ¹¹ and R ¹² , R ¹³ is preferably an alkyl group, and more preferably an unsubstituted alkyl group. The alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 and even more preferably 1 to 6.
The ring formed by combining R ¹¹ and R ¹² with each other is preferably a saturated ring, more preferably a 6-membered saturated ring, and even more preferably a piperidine ring.

R ¹¹ and R ¹² are preferably both a cyano group or an unsubstituted phenyl group, or bonded to each other to form a piperidine ring, and more preferably both are a cyano group or an unsubstituted phenyl group. .

In —COOR ¹⁴ represented by R ⁶ and R ⁷ , R ¹⁴ is preferably an alkyl group, and more preferably an unsubstituted alkyl group. The alkyl group preferably has 1 to 20 carbon atoms, and more preferably 5 to 15 carbon atoms.
In —SO ₂ R ¹⁵ each represented by R ⁶ and R ⁷ , R ¹⁵ is preferably an aryl group, and more preferably a phenyl group.

In an example in which R ⁶ and R ⁷ are bonded to each other to form a cyclic active methylene structure, it is preferable to form an active methylene structure (IXa-1) or an active methylene structure (IXa-4), and an active methylene structure ( More preferably, IXa-1) is formed.
More preferably, at least one of R ⁶ and R ⁷ represents a cyano group or is bonded to each other to form any one of the cyclic active methylene structures (IXa-1) to (IXa-6); Is more preferably a cyano group or bonded to each other to form any of the cyclic active methylene structures (IXa-1) and (IXa-4); both represent a cyano group or bonded to each other It is even more preferable to form any one of the cyclic active methylene structures (IXa-1) and (IXa-4).

  Preferred examples of the merocyanine compound represented by the general formula (IX) are represented by the following general formulas (IXa-a), (IXa-b), (IXa-c), and (IXa-d). Compounds are included. In particular, compounds represented by the following general formulas (IXa-a), (IXa-b), and (IXa-d) are preferable.

In the general formula ^(IXa-a), R ^6a and R ^7a has the general formula have the same meanings as R ⁶ and R ⁷ in (IXa), a preferred range is also the same. Among them, the compound that forms any one of the cyclic active methylene structures (IXa-1) to (IXa-6) is preferable not only from suppression of coloring but also from the viewpoint of light resistance.
In the general formula (IXa-b), R ^6b and R ^7b have the general formula have the same meanings as R ⁶ and R ⁷ in (IXa), a preferred range is also the same. Among them, each represents a cyano group, or the cyclic active methylene structures (IXa-1) to (IXa-6) (more preferably active methylene structures (IXa-1) or (IXa-4)), more preferably active A compound that forms any one of the methylene structures (IXa-1)) is preferable not only from suppression of coloring but also from the viewpoint of light resistance. In particular, compounds that are all cyano groups are preferred.
In the general formula (IXa-c), R ^6C and R ^7C are formulas have the same meanings as R ⁶ and R ⁷ in (IXa), a preferred range is also the same. Among them, one represents a cyano group and the other represents —COOR ¹⁴ (the definition and preferred range of R ¹⁴ are the same as those described above), or the cyclic active methylene structures (IXa-1) to (IXa-6). ) Are preferred.
In the general formula (IXa-d), R ¹¹ and R ¹² have the same meanings as those in the general formula (IXa), respectively, and preferred ranges thereof are also the same.

  The compounds represented by the general formulas (IXa-a), (IXa-b), (IXa-c), and (IXa-d) improve the light resistance of the merocyanine compound represented by the general formula (IX). Any compound represented by general formula (IXa-a), (IXa-b), (IXa-c), (IXa-d) and merocyanine represented by general formula (IX) It is preferable to use a mixed compound or a merocyanine compound represented by the general formula (IXa) because light resistance is improved. The mixing ratio of the merocyanine compound represented by the general formula (IX) to the general formulas (IXa-a), (IXa-b), (IXa-c), and (IXa-d) is 10 to 90:90. : 10 is preferable, 30 to 70:70 to 30 is more preferable, and 40 to 60:60 to 40 is most preferable.

  1.0-20 mass% is preferable with respect to a cellulose acylate, and, as for the addition amount of the wavelength dispersion regulator in this invention, 1.0-10 mass% is more preferable, and 1.5-8.0 mass% is further. Preferably, 2.0 to 6.0 mass% is most preferable.

  Preferred examples of the compounds represented by the general formulas (IXa-a), (IXa-b), (IXa-c), and (IXa-d) are shown below, but the present invention is limited to these specific examples. It is not something.

  The dope used in the method of the present invention preferably further contains a triazine compound represented by the general formula (II).

一般式（ＩＩ）中、Ｘ¹は、−ＮＲ⁴−、−Ｏ−又は−Ｓ−を表し；Ｘ²は、−ＮＲ⁵−、−Ｏ−又は−Ｓ−を表し；Ｘ³は、−ＮＲ⁶−、−Ｏ−又は−Ｓ−を表し；Ｒ¹、Ｒ²及びＲ³は、それぞれ、アルキル基、アルケニル基、アリール基又は複素環基を表し；Ｒ⁴、Ｒ⁵及びＲ⁶は、それぞれ、水素原子、アルキル基、アルケニル基、アリール基又は複素環基を表す。

In general formula (II), X ¹ represents —NR ⁴ —, —O— or —S—; X ² represents —NR ⁵ —, —O— or —S—; X ³ represents — NR ^6- , -O- or -S-; R ¹ , R ² and R ³ each represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; R ⁴ , R ⁵ and R ⁶ are Respectively represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.

In the general formula (II), R ¹ , R ² , and R ³ each independently represents an alkyl group, an alkenyl group, an aromatic ring group, or a heterocyclic group, and more preferably an aromatic ring or a heterocyclic ring. The aromatic ring represented by each of R ¹ , R ² , and R ³ is preferably phenyl or naphthyl, and particularly preferably phenyl.

R ¹ , R ² , and R ³ may have a substituent on the aromatic ring or the heterocyclic ring. Examples of substituents include halogen atoms, hydroxyl groups, cyano groups, nitro groups, carboxyl groups, alkyl groups, alkenyl groups, aryl groups, alkoxy groups, alkenyloxy groups, aryloxy groups, acyloxy groups, alkoxycarbonyl groups, alkenyls. Oxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl group, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide Groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups.

When R ¹ , R ² , and R ³ represent a heterocyclic group, the heterocyclic ring preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent described above. These substituents may be further substituted with the above substituents.

The alkyl group represented by each of R ⁴ , R ⁵ and R ⁶ may be a cyclic alkyl group or a chain alkyl group, but is preferably a chain alkyl group, rather than a chain alkyl group having a branch, A linear alkyl group is more preferred. The number of carbon atoms in the alkyl group is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, further preferably 1 to 8, and 1 to 6. Is most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy, ethoxy) and an acyloxy group (for example, acryloyloxy, methacryloyloxy).

The alkenyl group represented by each of R ⁴ , R ⁵ and R ⁶ may be a cyclic alkenyl group or a chain alkenyl group, but is preferably a chain alkenyl group, more preferably than a branched chain alkenyl group. A linear alkenyl group is more preferred. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, and 2 to 6 Most preferably. The alkenyl group may have a substituent. Examples of the substituent include the same substituents as those of the alkyl group described above.

The aromatic ring group (aryl group) and heterocyclic group represented by R ⁴ , R ⁵ and R ⁶ are the same as the aromatic ring and heterocyclic ring represented by R ¹ , R ² and R ³ , respectively. It is the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent include the same substituents as those for the aromatic ring and heterocyclic ring of R ¹ , R ² and R ^3. Can be mentioned.

  Although the preferable example of the triazine type compound represented by general formula (II) of this invention below is shown, this invention is not limited to these specific examples.

  Although the addition of the wavelength dispersion adjusting agent and the triazine compound in the present invention may be added in advance when preparing a mixed solution of cellulose acylate, either a polymer solution (dope solution) is prepared in advance and casted. It may be added at this point. In the latter case, for example, a static mixer (Toray Engineering Co., Ltd.) is used for in-line addition and mixing of a solution in which a polymer is dissolved in a solvent and a solution in which a wavelength dispersion adjusting agent and a small amount of cellulose acylate are dissolved. In-line mixers such as SWJ (Toray static type in-tube mixer Hi-Mixer) are preferably used. The post-added wavelength dispersion adjusting agent may be mixed with a matting agent at the same time, its retardation control agent, plasticizer (for example, triphenyl phosphate, biphenyl phosphate, etc.), deterioration inhibitor, peeling accelerator. Additives such as these may be mixed. When using an in-line mixer, it is preferable to concentrate and dissolve under high pressure, and the type of the pressurized container is not particularly limited, as long as it can withstand a predetermined pressure and can be heated and stirred under pressure. The pressure vessel is appropriately provided with other instruments such as a pressure gauge and a thermometer. The pressurization may be performed by a method of injecting an inert gas such as nitrogen gas or by increasing the vapor pressure of the solvent by heating. Heating is preferably performed from the outside. For example, a jacket type is preferable because temperature control is easy. The heating temperature with the addition of the solvent is preferably a temperature not lower than the boiling point of the solvent used and in a range where the solvent does not boil. For example, the heating temperature is preferably set in the range of 30 to 150 ° C. The pressure is adjusted so that the solvent does not boil at the set temperature. After dissolution, it is taken out from the container while cooling, or extracted from the container with a pump or the like and cooled with a heat exchanger or the like, and used for film formation. Although the cooling temperature at this time may be cooled to room temperature, it is more preferable to cool to a temperature 5 to 10 ° C. lower than the boiling point and perform casting at that temperature because the dope viscosity can be reduced.

In addition, the wavelength dispersion adjusting agent and the triazine compound represented by the general formula (II) in the present invention can be used alone or in combination of two or more.
1.0-20 mass% is preferable with respect to a cellulose acylate, and, as for the addition amount of the wavelength dispersion regulator in this invention, 1.0-10 mass% is more preferable, and 1.5-8.0 mass% is further. Preferably, 2.0 to 6.0 mass% is most preferable.
Further, the triazine compound represented by the general formula (II) in the polymer film of the present invention is contained in an amount of 10% by mass (0.1 times) to 1000% by mass (10 times) with respect to the wavelength dispersion adjusting agent. It is preferably 20% by mass (0.2 times) or more and 750% by mass (7.5 times) or less.
In the present invention, the method for adding the wavelength dispersion adjusting agent and the triazine compound represented by the general formula (II) includes a wavelength dispersion adjusting agent and a triazine represented by the general formula (II) in an organic solvent such as alcohol, methylene chloride, or dioxolane. After dissolving the system compound, it may be added to the cellulose acylate solution (dope), or may be added directly to the dope composition.

  The triazine compound represented by the general formula (II) has the action of suppressing the decomposition of the merocyanine compound represented by the general formula (IX) and improving the light resistance. It is preferable to use a mixture of the triazine compound and the merocyanine compound represented by the general formula (IX).

Stabilizer:
A stabilizer may be added to the dope used in the method of the present invention for the purpose of suppressing decomposition / modification of the polymer itself.
The stabilizer is added to reduce the coloration or thermal degradation of the polymer during film formation, etc., and is a compound that suppresses the decomposition and modification of the polymer itself. Agent, peroxide decomposer, metal deactivator, acid scavenger, and light stabilizer. In the present invention, any stabilizer may be used, but among the stabilizers, it is preferable to use an antioxidant or a radical inhibitor, and it is more preferable to use an antioxidant. The addition amount is preferably the same addition amount as that of the wavelength dispersion adjusting agent from the viewpoint of expression of the effect, and is preferably 0.2 to 20% by mass with respect to at least one kind of polymer.

Examples of the antioxidant include a phosphoric acid compound having a phosphorous acid skeleton, a sulfur compound having a thioether structure, a phosphate ester compound having a pentaerythritol skeleton structure, or a lactone compound having a lactone structure The radical inhibitor is preferably a phenolic compound having an aromatic ring substituted with a hydroxyl group, or an amine compound having a substituted or unsubstituted amino group, and the peroxide decomposing agent is a phenolic compound. Compounds and amine compounds are preferable. As the metal deactivator, amide compounds having an amide bond are preferable. As the acid scavenger, an epoxy compound having an epoxy group is preferable. As the light stabilizer, Amine-based compounds are preferred.
These stabilizers may be used alone or in combination of two or more, or may be a compound having two or more functions in the same molecule.

  The stabilizer is preferably sufficiently low in volatility at high temperatures, and preferably contains at least one stabilizer having a molecular weight of 500 or more. Furthermore, the molecular weight is preferably 500 to 4000, more preferably 530 to 3500, and particularly preferably 550 to 3000. If the molecular weight is 500 or more, the heat volatility is easily suppressed, and if the molecular weight is 4000 or less, the compatibility with cellulose acylate is particularly improved.

  As the stabilizer, a commercially available stabilizer may be used. For example, cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl) phosphite (manufactured by ADEKA Corporation, “Adeka Stub”) It is preferable to use a phosphate ester-based antioxidant having a pentaerythritol skeleton structure such as PEP-36 ").

Other additives:
In the dope used in the method of the present invention, cellulose acylate as a main component and the predetermined aromatic group-containing oligomer are added together with one or more additives within a range not impairing the effects of the present invention. Also good. Examples of the additive include a retardation adjusting agent (preferable range of the addition amount with respect to the mass of cellulose acylate is 0.01 to 10% by mass, hereinafter, the numerical range in parentheses is synonymous), ultraviolet absorber ( 0.001 to 20% by mass), fine particle powder having an average particle size of 5 to 3000 nm (0.001 to 1% by mass), fluorine-based surfactant (0.001 to 1% by mass), release agent (0 0.0001 to 1% by mass), an anti-degradation agent (0.0001 to 1% by mass), and an infrared absorber (0.001 to 1% by mass).
However, the cellulose acylate film produced by the production method of the present invention does not contain additives other than aromatic group-containing oligomers, or contains additives other than aromatic group-containing oligomers. One feature is that high Re and high Rth can be achieved even in an embodiment containing only an additive that does not substantially affect the in-plane retardation and / or the thickness direction retardation. .

Next, the properties and uses of the cellulose acylate film produced by the method of the present invention will be described.
2. Properties of cellulose acylate film (optical properties)
As described above, according to the method of the present invention, a cellulose acylate film having high Re and high Rth can be produced.
Specifically, a cellulose acylate film having Re of 5 to 20 nm and Rth of 90 to 150 nm can be produced. The film is useful as an optical member of a liquid crystal display device, and particularly useful as a member for optical compensation in a twisted alignment mode such as a TN mode.
In addition, a cellulose acylate film having Re of 5 to 50 nm and Rth of 90 to 150 nm can be produced. The film is useful as an optical member of a liquid crystal display device, and particularly useful as an optical compensation member for a VA mode vertical alignment mode.

The cellulose acylate film produced by the method of the present invention is preferably from the viewpoint of yellowness in a halftone display when a twisted alignment mode liquid crystal display device is observed from the lateral direction,
0.9 <Rth (450) / Rth (550) ≦ 1.5 Formula (1)
More preferably,
1.0 <Rth (450) / Rth (550) <1.5 Formula (1 ′)
More preferably,
1.1 <Rth (450) / Rth (550) <1.5 Formula (1 ″)
Meet.
Here, Rth (550) represents the thickness direction retardation at a wavelength of 550 nm, and Rth (450) represents the thickness direction retardation at a wavelength of 450 nm.

  In this specification, Re and Rth (unit: nm) are obtained according to the following method. First, the film was conditioned at 25 ° C. and 60% relative humidity for 24 hours, and then a prism coupler (MODEL2010 Prism Coupler: manufactured by Metricon) was used. At 25 ° C. and 60% relative humidity, the following formula was used: The average refractive index (n) represented by (2) is obtained.

Formula (2): n = (n _TE × 2 + n _TM ) / 3
[ _Where n _TE is a refractive index measured with polarized light in the film plane direction, and n _TM is a refractive index measured with polarized light in the film surface normal direction. ]

In this specification, Re (λnm) and Rth (λnm) represent in-plane retardation and retardation in the thickness direction at a wavelength λ (unit: nm), respectively. Re (λnm) is measured by making light having a wavelength of λnm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λnm) is calculated by the following method.
Rth (λnm) is Re (λnm), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light is incident at a wavelength of λ nm in 10 ° steps from the normal direction to 50 ° on one side with respect to the normal direction of the film (with the direction of the rotation axis as the rotation axis), and a total of 6 points are measured. KOBRA 21ADH or WR is calculated based on the measured retardation value, average refractive index, and input film thickness value.
In the above, there is no particular description regarding λ, and when only Re and Rth are described, it represents a value measured using light with a wavelength of 590 nm. In addition, in the case of a film having a retardation value of zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, the retardation value at a tilt angle larger than that tilt angle. After changing its sign to negative, KOBRA 21ADH or WR calculates.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (3) and (4).

［式中、Ｒｅ（θ）は法線方向から角度θ傾斜した方向におけるレタ−デーション値を表す。また、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘおよびｎｙに直交する厚み方向の屈折率を表し、ｄはフィルムの膜厚を表す。］

[In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. Further, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, nz represents the refractive index in the thickness direction perpendicular to nx and ny, and d Represents the film thickness of the film. ]

    Formula (4): Rth = ((nx + ny) / 2−nz) × d

When the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film without a so-called optical axis, Rth (λnm) is calculated by the following method.
Rth (λnm) is from -50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λnm) being the slow axis (indicated by KOBRA 21ADH or WR) as the tilt axis (rotation axis). Measured at 11 points by making light of wavelength λ nm incident from each inclined direction in 10 degree steps, and KOBRA 21ADH or WR is calculated based on the measured retardation value, average refractive index, and input film thickness value. To do. By inputting these average refractive index and film thickness, KOBRA 21ADH or WR calculates nx, ny, and nz. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

(Slow axis)
In the production method of the present invention, the direction of the in-plane slow axis of the produced cellulose acylate is determined by the stretching direction in the stretching step performed before the heat treatment step. In the cellulose acylate film, it is preferable from the viewpoint of polarizing plate processing that the angle formed between the longitudinal direction (conveying direction) during production and the in-plane slow axis of the film is orthogonal. The angle formed between the longitudinal direction of the film and the slow axis is preferably 0 ± 10 ° or 90 ± 10 °, more preferably 0 ± 5 ° or 90 ± 5 °, and 0 ± 3 ° or 90 °. More preferably, it is ± 3 °, and in some cases, it is preferably 0 ± 1 ° or 90 ± 1 °, and most preferably 90 ± 1 °.

(Film thickness)
The film thickness of the cellulose acylate film is preferably 20 μm to 180 μm, more preferably 30 μm to 160 μm, and even more preferably 40 μm to 120 μm. A film thickness of 20 μm or more is preferable in terms of handling properties when processing into a polarizing plate or the like and curling suppression of the polarizing plate. Further, the film thickness unevenness of the cellulose acylate film is preferably 0 to 2% in both the transport direction and the width direction, more preferably 0 to 1.5%, and particularly preferably 0 to 1%. preferable.

(Moisture permeability)
The moisture permeability of the cellulose acylate film is preferably 100 g / (m ² · day) or more in terms of 80 μm. By using a film having a moisture permeability of 80 g in terms of 100 g / (m ² · day) or more, the film can be easily bonded directly to the polarizing film. The moisture permeability of the 80μm ^{terms, 100~1500g / (m 2 · day} ) , more ^{preferably, 200~1000g / (m 2 · day} ) , and even more preferably 300~800g / (m ² · day) .
When the cellulose acylate film is used as an outer protective film that is not disposed between the polarizing film and the liquid crystal cell, the moisture permeability of the cellulose acylate film is less than 500 g / (m ² · day) in terms of 80 μm. Preferably, it is 100 to 450 g / (m ² · day), more preferably 100 to 400 g / (m ² · day), and even more preferably 150 to 300 g / (m ² · day). By doing in this way, durability of the polarizing plate with respect to humidity or wet heat improves, and a highly reliable liquid crystal display device can be provided.

(ΔHc)
The cellulose acylate film preferably has a crystallization heat ΔHc of 1.0 to 4.0 J / g, and more preferably 2.0 to 3.0 J / g. By making it within this range, it is possible to expand the expression of Re.

(Coloring)
The cellulose acylate film is preferably less colored and excellent in colorless transparency. Specifically, the absorption at 400 nm is preferably 0.2 or less, and more preferably 0.1 or less.

3. Use of Cellulose Acylate Film The cellulose acylate film produced by the production method of the present invention can be used for various uses. In particular, it is useful as an optical member of a liquid crystal display device, and can be used, for example, as an optical compensation film or a part thereof, or as a protective film for a polarizing plate. Hereinafter, although the aspect of the cellulose acylate film useful for the liquid crystal display device of each mode is each demonstrated, it is not limited to the following aspects.

Cellulose acylate film for twisted alignment mode liquid crystal display:
The cellulose acylate film produced by the production method of the present invention is TN as an optical compensation film or a part thereof, or as a protective film for a polarizing plate (preferably an inner protective film disposed on the liquid crystal cell side). It can be used for a twisted alignment mode liquid crystal display device such as a mode. The cellulose acylate film used in the twisted alignment mode liquid crystal display device preferably has Re of 5 to 20 nm and Rth of 90 to 150 nm.

  In one example of the cellulose acylate film used in the twisted alignment mode liquid crystal display device, the cellulose acylate film is used as a support of an optical compensation film having a support and an optically anisotropic layer made of a liquid crystal composition thereon. Is used. You may use the said cellulose acylate film as a support body, after performing the surface treatment etc. which are mentioned later suitably.

The liquid crystal composition used for forming the optically anisotropic layer made of the liquid crystal composition is preferably a liquid crystal composition capable of forming a nematic phase and a smectic phase. Liquid crystal compounds are generally classified into rod-like and disc-like liquid crystal compounds based on their molecular shapes, but any shape of liquid crystal compounds may be used in the present invention.
The thickness of the optically anisotropic layer made of the liquid crystal composition is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.

(Material used for optically anisotropic layer made of liquid crystal composition)
(1) Discotic liquid crystal compound (discotic liquid crystal compound)
Examples of discotic liquid crystalline compounds include C.I. Destrade et al., Mol. Cryst. 71, 111 (1981), benzene derivatives described in C.I. Destrade et al., Mol. Cryst. 122, 141 (1985), Physics lett, A, 78, 82 (1990); Kohne et al., Angew. Chem. 96, page 70 (1984) and the cyclohexane derivatives described in J. Am. M.M. Lehn et al. Chem. Commun. , 1794 (1985), J. Am. Zhang et al., J. Am. Chem. Soc. 116, 2655 (1994), azacrown type and phenylacetylene type macrocycles are included.

The discotic liquid crystalline compound has a liquid crystallinity having a structure in which a linear alkyl group, an alkoxy group, or a substituted benzoyloxy group is radially substituted as a side chain of the mother nucleus with respect to the mother nucleus at the molecular center. The compounds shown are also included. The molecule or the assembly of molecules is preferably a compound having rotational symmetry and imparting a certain orientation.
When an optically anisotropic layer is formed from a discotic liquid crystalline compound, the compound finally contained in the optically anisotropic layer no longer needs to exhibit liquid crystallinity.
Preferred examples of the discotic liquid crystalline compound include paragraph numbers [0052] in JP-A-8-50206 and JP-A-2006-76992, and paragraph numbers [0040] in JP-A-2007-2220. ] To [0063]. Moreover, about superposition | polymerization of a discotic liquid crystalline compound, Unexamined-Japanese-Patent No. 8-27284 has description. For example, a discotic liquid crystalline compound represented by the following general formula (DI) is particularly preferable because it exhibits high birefringence.

In the general formula (DI), Y ¹ , Y ² and Y ³ each independently represent a methine group or a nitrogen atom which may be substituted.

When Y ¹ , Y ² and Y ³ are methine, the hydrogen atom of methine may be replaced with a substituent. Examples of the substituent that methine may have include an alkyl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an acyloxy group, an acylamino group, an alkoxycarbonylamino group, an alkylthio group, an arylthio group, a halogen atom, and A cyano group can be mentioned as a preferred example. Among these substituents, an alkyl group, an alkoxy group, an alkoxycarbonyl group, an acyloxy group, a halogen atom and a cyano group are more preferable, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and a carbon number A 2-12 alkoxycarbonyl group, a C2-C12 acyloxy group, a halogen atom, and a cyano group are more preferable.
Y ¹ , Y ² and Y ³ are more preferably methine, and more preferably unsubstituted, in view of the ease of synthesis of the compound and the cost.

L ¹ , L ² and L ³ each independently represents a single bond or a divalent linking group.
When L ¹ , L ² and L ³ are divalent linking groups, each independently represents —O—, —S—, —C (
It is preferably a divalent linking group selected from the group consisting of ═O) —, —NR ⁷ —, —CH═CH—, —C≡C—, a divalent cyclic group, and combinations thereof. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group, or a hydrogen atom. Preferably, it is a hydrogen atom.

The divalent cyclic group in L ¹ , L ² and L ³ is a divalent linking group having at least one cyclic structure (hereinafter sometimes referred to as a cyclic group). The cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferred examples of the aromatic ring include a benzene ring and a naphthalene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. The cyclic group is more preferably an aromatic ring or a heterocyclic ring. The divalent cyclic group in the present invention is more preferably a divalent linking group consisting of only a cyclic structure (including a substituent) (hereinafter the same).

Of the divalent cyclic groups represented by L ¹ , L ² and L ³ , the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As the cyclic group having a naphthalene ring, a naphthalene-1,5-diyl group and a naphthalene-2,6-diyl group are preferable. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group.

The divalent cyclic group represented by L ¹ , L ² and L ³ may have a substituent. Examples of the substituent include a halogen atom (preferably a fluorine atom and a chlorine atom), a cyano group, a nitro group, an alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, and 2 to 2 carbon atoms. 16 alkynyl group, halogen-substituted alkyl group having 1 to 16 carbon atoms, alkoxy group having 1 to 16 carbon atoms, acyl group having 2 to 16 carbon atoms, alkylthio group having 1 to 16 carbon atoms, 2 carbon atoms ˜16 acyloxy groups, alkoxycarbonyl groups having 2 to 16 carbon atoms, carbamoyl groups, carbamoyl groups substituted with alkyl groups having 2 to 16 carbon atoms, and acylamino groups having 2 to 16 carbon atoms are included.

L ¹ , L ² and L ³ are each a single bond, * —O—CO—, * —CO—O—, * —CH═CH—, * —C≡C—, * —divalent cyclic group— * -O-CO-divalent cyclic group-, * -CO-O-divalent cyclic group-, * -CH = CH-divalent cyclic group-, * -C≡C-divalent cyclic group Group-, * -divalent cyclic group-O-CO-, * -divalent cyclic group-CO-O-, * -divalent cyclic group-CH = CH- and * -divalent cyclic group- C≡C— is preferred. In particular, a single bond, * —CH═CH—, * —C≡C—, * —CH═CH—divalent cyclic group— and * —C≡C—divalent cyclic group— are preferable, and a single bond is Most preferred. Here, * represents the position bonded to the 6-membered ring side including Y ¹¹ , Y ¹² and Y ¹³ in the general formula (DI).

In the general formula (DI), H ¹ , H ² and H ³ each independently represent a group of the general formula (IA) or (IB).

In formula (IA), YA ¹ and YA ² each independently represents a methine or nitrogen atom; XA represents an oxygen atom, a sulfur atom, methylene or imino;
* Represents the position of bonding to the L ^{1 to} L ³ side in the above general formula (DI);
** represents a position to be bonded to the R ^{1 to} R ³ side in the general formula (DI).

In the general formula (IB), YB ¹ and YB ² each independently represent a methine or nitrogen atom; XB represents an oxygen atom, a sulfur atom, methylene or imino;
* Represents the position of bonding to the L ^{1 to} L ³ side in the above general formula (DI);
** represents a position to be bonded to the R ^{1 to} R ³ side in the general formula (DI).

In general formula (DI), R < ¹ >, R < ² > and R < ³ > represent the following general formula (IR) each independently.

General formula (IR)
*-(-L ¹⁰¹ -Q ² ) _n1 -L ¹⁰² -L ¹⁰³ -Q ¹
In the general formula (I-R), * represents a position bonded to the H ^{1 to} H ³ side in the general formula (DI).
L ¹⁰¹ represents a single bond or a divalent linking group. When L ²¹ is a divalent linking group, the group consisting of —O—, —S—, —C (═O) —, —NR ⁷ —, —CH═CH—, —C≡C—, and combinations thereof It is preferably a divalent linking group selected more. R ⁷ is an alkyl group having 1 to ⁷ carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, and more preferably a methyl group, an ethyl group, or a hydrogen atom. Preferably, it is a hydrogen atom.

L ¹⁰¹ is a single bond, ***-O-CO-, ***-CO-O-, ***-CH = CH- and ***-C≡C- (where *** is general Any one of the formula (IR) is preferable, and a single bond is more preferable.

Q ² represents a divalent group (cyclic group) having at least one kind of cyclic structure. As such a cyclic group, a cyclic group having a 5-membered ring, a 6-membered ring, or a 7-membered ring is preferable, a cyclic group having a 5-membered ring or a 6-membered ring is more preferable, and a cyclic group having a 6-membered ring is Further preferred. The cyclic structure contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Preferable examples of the aromatic ring include a benzene ring, a naphthalene ring, an anthracene ring, and a phenanthrene ring. A preferable example of the aliphatic ring is a cyclohexane ring. Preferred examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring.

Of Q ^2, the cyclic group having a benzene ring is preferably a 1,4-phenylene group. As the cyclic group having a naphthalene ring, naphthalene-1,4-diyl group, naphthalene-1,5-diyl group, naphthalene-1,6-diyl group, naphthalene-2,5-diyl group, naphthalene-2,6 -A diylnaphthalene-2,7-diyl group is preferred. The cyclic group having a cyclohexane ring is preferably a 1,4-cyclohexylene group. The cyclic group having a pyridine ring is preferably a pyridine-2,5-diyl group. The cyclic group having a pyrimidine ring is preferably a pyrimidine-2,5-diyl group. Among these, a 1,4-phenylene group, a naphthalene-2,6-diyl group, and a 1,4-cyclohexylene group are particularly preferable.

Q ² may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, alkenyl group having 2 to 16 carbon atoms, carbon An alkynyl group having 2 to 16 atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, and 1 to 16 carbon atoms An alkylthio group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.

  n1 represents the integer of 0-4. n1 is preferably an integer of 1 to 3, and more preferably 1 or 2.

L ¹⁰² is **-O-, **-O-CO-, **-CO-O-, **-O-CO-O-, **-S-, **-NH-, ** —SO ₂ —, ** — CH ₂ —, ** — CH═CH—, or ** — C≡C— is represented, and ** represents a position bonded to the Q ² side.
L ¹⁰² is preferably ** — O—, ** — O—CO—, ** — CO—O—, ** — O—CO—O—, ** — CH ₂ —, ** — CH. ═CH—, ** — C≡C—, more preferably ** — O—, ** — O—CO—, ** — O—CO—O—, ** — CH ₂ —. . When L ¹⁰² is a group containing a hydrogen atom, the hydrogen atom may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ¹⁰³ is —O—, —S—, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH— and —C≡C— and combinations thereof. Represents a divalent linking group selected from the group consisting of Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred. By being substituted by these substituents, when preparing a liquid crystalline composition from the liquid crystalline compound of the present invention, the solubility in a solvent to be used can be improved.

L ¹⁰³ is preferably selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. L ¹⁰³ preferably contains 1 to 20 carbon atoms, more preferably 2 to 14 carbon atoms. Further, L ¹⁰³ preferably contains 1 to 16 —CH ₂ —, and more preferably ₂ to 12 —CH ₂ —.

Q ¹ represents a polymerizable group or a hydrogen atom. When the liquid crystalline compound of the present invention is used for an optical compensation film, it is preferable that the phase difference does not change due to heat. Therefore, when used for an optical film or the like, Q ¹ is preferably a polymerizable group. The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.

  Furthermore, the polymerizable group is particularly preferably a functional group capable of addition polymerization reaction. Such a polymerizable group is preferably a polymerizable ethylenically unsaturated group or a ring-opening polymerizable group.

  Examples of the polymerizable ethylenically unsaturated group include the following formulas (M-1) to (M-6).

In formulas (M-3) and (M-4), R represents a hydrogen atom or an alkyl group, preferably a hydrogen atom or a methyl group.
Among the formulas (M-1) to (M-6), (M-1) or (M-2) is preferable, and (M-1) is more preferable.

  The ring-opening polymerizable group is preferably a cyclic ether group, and more preferably an epoxy group or an oxetanyl group.

  Among the compounds of the general formula (DI), a compound represented by the following general formula (DI ′) is more preferable.

In the general formula (DI ′), Y ¹¹ , Y ¹² and Y ¹³ each independently represent methine or a nitrogen atom, methine is preferred, and methine is preferably unsubstituted.

R ¹¹ , R ¹² and R ¹³ each independently represent the following general formula (I′-A), the following general formula (I′-B) or the following general formula (I′-C). In order to reduce the wavelength dispersion of intrinsic birefringence, general formula (I′-A) or general formula (I′-C) is preferable, and general formula (I′-A) is more preferable. R ¹¹ , R ¹² and R ¹³ are preferably the same R ¹¹ = R ¹² = R ¹³ .

In general formula (I′-A), A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ each independently represent a methine or nitrogen atom.
At least one of A ¹¹ and A ¹² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ¹³ , A ¹⁴ , A ¹⁵ and A ¹⁶ , at least three of them are preferably methine, more preferably all methine. Furthermore, methine is preferably unsubstituted.
Examples of substituents when A ¹¹ , A ¹² , A ¹³ , A ¹⁴ , A ¹⁵ or A ¹⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ¹ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In general formula (I′-B), A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ and A ²⁶ each independently represents a methine or nitrogen atom.
At least one of A ²¹ and A ²² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
Of A ²³ , A ²⁴ , A ²⁵ and A ²⁶ , at least three of them are preferably methine, more preferably all methine.
Examples of substituents when A ²¹ , A ²² , A ²³ , A ²⁴ , A ²⁵ or A ²⁶ is methine include halogen atoms (fluorine atoms, chlorine atoms, bromine atoms, iodine atoms), cyano groups, nitro groups An alkyl group having 1 to 16 carbon atoms, an alkenyl group having 2 to 16 carbon atoms, an alkynyl group having 2 to 16 carbon atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, and 1 carbon atom -16 alkoxy group, C2-C16 acyl group, C1-C16 alkylthio group, C2-C16 acyloxy group, C2-C16 alkoxycarbonyl group, carbamoyl group, An alkyl-substituted carbamoyl group having 2 to 16 carbon atoms and an acylamino group having 2 to 16 carbon atoms are included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable.
X ² represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

In general formula (I′-C), A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ and A ³⁶ each independently represents a methine or nitrogen atom.
At least one of A ³¹ and A ³² is preferably a nitrogen atom, and more preferably both are nitrogen atoms.
At least three of A ³³ , A ³⁴ , A ³⁵ and A ³⁶ are preferably methine, more preferably methine.
When A ³¹ , A ³² , A ³³ , A ³⁴ , A ³⁵ or A ³⁶ is methine, the methine may have a substituent. Examples of the substituent include a halogen atom (fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, nitro group, alkyl group having 1 to 16 carbon atoms, alkenyl group having 2 to 16 carbon atoms, carbon An alkynyl group having 2 to 16 atoms, an alkyl group substituted with a halogen having 1 to 16 carbon atoms, an alkoxy group having 1 to 16 carbon atoms, an acyl group having 2 to 16 carbon atoms, and 1 to 16 carbon atoms An alkylthio group having 2 to 16 carbon atoms, an alkoxycarbonyl group having 2 to 16 carbon atoms, a carbamoyl group, an alkyl-substituted carbamoyl group having 2 to 16 carbon atoms, and an acylamino group having 2 to 16 carbon atoms. included. Among these, a halogen atom, a cyano group, an alkyl group having 1 to 6 carbon atoms, and an alkyl group substituted with a halogen having 1 to 6 carbon atoms are preferable, a halogen atom, an alkyl group having 1 to 4 carbon atoms, An alkyl group substituted with a halogen having 1 to 4 carbon atoms is more preferable, and a halogen atom, an alkyl group having 1 to 3 carbon atoms, and a trifluoromethyl group are more preferable. X ³ represents an oxygen atom, a sulfur atom, methylene or imino, preferably an oxygen atom.

L ^{11 in} the general formula (I′-A), L ^{21 in} the general formula (I′-B), and L ³¹ in the general formula (I′-C) are each independently —O—, —C (═O) —, —O—CO—, —CO—O—, —O—CO—O—, —S—, —NH—, —SO ₂ —, —CH ₂ —, —CH═CH— or —C≡C— is represented. Preferably, —O—, —C (═O) —, —O—CO—, —CO—O—, —O—CO—O—, —CH ₂ —, —CH═CH—, —C≡C are preferable. —, More preferably —O—, —O—CO—, —CO—O—, —O—CO—O—, —C≡C—. In particular, L ¹¹ in the general formula (I′-A) that can be expected to have small intrinsic birefringence wavelength dispersibility is particularly preferably —O—, —CO—O—, —C≡C—. CO-O- is preferable because it can exhibit a discotic nematic phase at a higher temperature. When the above group is a group containing a hydrogen atom, the hydrogen atom may be replaced with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and an alkoxy group having 1 to 6 carbon atoms. , An acyl group having 2 to 6 carbon atoms, an alkylthio group having 1 to 6 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and 2 to 2 carbon atoms Preferred examples include a carbamoyl group substituted with 6 alkyls and an acylamino group having 2 to 6 carbon atoms, and a halogen atom and an alkyl group having 1 to 6 carbon atoms are more preferred.

L ^{12 in} the general formula (I′-A), L ^{22 in} the general formula (I′-B), and L ³² in the general formula (I′-C) are each independently —O—, —S. A divalent linking group selected from the group consisting of —, —C (═O) —, —SO ₂ —, —NH—, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. Represents. Here, the hydrogen atoms of —NH—, —CH ₂ —, and —CH═CH— may be substituted with a substituent. Examples of such a substituent include a halogen atom, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, an alkyl group having 1 to 6 carbon atoms, an alkyl group substituted with a halogen having 1 to 6 carbon atoms, and 1 carbon atom. -6 alkoxy group, C2-C6 acyl group, C1-C6 alkylthio group, C2-C6 acyloxy group, C2-C6 alkoxycarbonyl group, carbamoyl group, Preferred examples include a carbamoyl group substituted with an alkyl having 2 to 6 carbon atoms and an acylamino group having 2 to 6 carbon atoms, and a halogen atom, a hydroxyl group, and an alkyl group having 1 to 6 carbon atoms are more preferable. A halogen atom, a methyl group, and an ethyl group are preferable.

L ¹² , L ²² and L ³² are each independently selected from the group consisting of —O—, —C (═O) —, —CH ₂ —, —CH═CH—, —C≡C—, and combinations thereof. It is preferable to be selected.

L ¹² , L ²² and L ³² each independently preferably have 1 to 20 carbon atoms, and more preferably 2 to 14 carbon atoms. The number of carbon atoms is preferably 2 to 14, more preferably 1 to 16 —CH ₂ —, and still more preferably ₂ to 12 —CH ₂ —.

The number of carbon atoms constituting L ¹² , L ²² , and L ³² affects the phase transition temperature of the liquid crystal and the solubility of the compound in the solvent. Generally the more increased the number of carbon atoms, transition temperature of the discotic nematic phase from (N _D phase) to the isotropic liquid tends to decrease. Further, the solubility in a solvent generally tends to improve as the number of carbon atoms increases.

Q ^{11 in} the general formula (I′-A), Q ^{21 in} the general formula (I′-B), and Q ³¹ in the general formula (I′-C) each independently represent a polymerizable group or a hydrogen atom. To express. Q ¹¹ , Q ²¹ and Q ³¹ are preferably a polymerizable group. The polymerization reaction is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. That is, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Hereinafter, examples of the polymerizable group are the same as described above, and preferable examples are also the same as described above. Specific examples of the polymerizable group represented by Q ¹¹ , Q ²¹ , and Q ³¹ are the same as those described for the polymerizable group Q ¹ in the general formula (IR), and the preferred ranges are also the same. Q ¹¹ , Q ²¹ and Q ³¹ may be the same or different from each other, but the same case is preferable.

  Specific examples of the compound represented by the general formula (DI) include the exemplified compounds described in [Chemical Formula 13] to [Chemical Formula 43] of [0052] of JP-A-2006-76992, and JP-A-2007-2220. The compound shown in [Chemical Formula 13] of [Chemical Formula 13] to [0063] of [0040] in Japanese Patent Publication No. Gazette. However, it is not limited to these compounds.

  The above compound can be synthesized by various methods, for example, by the method described in JP-A 2007-2220, [0064] to [0070].

一般式（ＤＩＩ）中、ＬＱ（又はＱＬ）は、二価の連結基（Ｌ）と重合性基（Ｑ）との組み合わせを意味する。
一般式（ＤＩＩ）において、二価の連結基（Ｌ）は、アルキレン基、アルケニレン基、アリーレン基、−ＣＯ−、−ＮＨ−、−Ｏ−、−Ｓ−およびそれらの組み合わせからなる群より選ばれる二価の連結基であることが好ましい。二価の連結基（Ｌ）は、アルキレン基、アリーレン基、−ＣＯ−、−ＮＨ−、−Ｏ−および−Ｓ−からなる群より選ばれる二価の基を少なくとも二つ組み合わせた二価の連結基であることがさらに好ましい。二価の連結基（Ｌ）は、アルキレン基、アリーレン基、−ＣＯ−および−Ｏ−からなる群より選ばれる二価の基を少なくとも二つ組み合わせた二価の連結基であることが最も好ましい。アルキレン基の炭素原子数は、１〜１２であることが好ましい。アルケニレン基の炭素原子数は、２〜１２であることが好ましい。アリーレン基の炭素原子数は、６〜１０であることが好ましい。 For example, as the discotic liquid crystal compound, a compound represented by the following general formula (DII) may be used together with or instead of the compound represented by the general formula (DI).

In general formula (DII), LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable group (Q).
In the general formula (DII), the divalent linking group (L) is selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S—, and combinations thereof. It is preferable that it is a bivalent coupling group. The divalent linking group (L) is a divalent combination of at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO-, -NH-, -O-, and -S-. More preferably, it is a linking group. The divalent linking group (L) is most preferably a divalent linking group in which at least two divalent groups selected from the group consisting of an alkylene group, an arylene group, -CO- and -O- are combined. . The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms in the arylene group is preferably 6-10.

Examples of the divalent linking group (L) are shown below. The left side is bonded to the discotic core (D), and the right side is bonded to the polymerizable group (Q). AL represents an alkylene group or an alkenylene group, and AR represents an arylene group. The alkylene group, alkenylene group and arylene group may have a substituent (eg, an alkyl group).
L1: -AL-CO-O-AL-,
L2: -AL-CO-O-AL-O-,
L3: -AL-CO-O-AL-O-AL-,
L4: -AL-CO-O-AL-O-CO-,
L5: -CO-AR-O-AL-,
L6: -CO-AR-O-AL-O-,
L7: -CO-AR-O-AL-O-CO-,
L8: -CO-NH-AL-,
L9: -NH-AL-O-,
L10: -NH-AL-O-CO-,

L11: -O-AL-,
L12: -O-AL-O-,
L13: -O-AL-O-CO-,
L14: -O-AL-O-CO-NH-AL-,
L15: -O-AL-S-AL-,
L16: -O-CO-AL-AR-O-AL-O-CO-,
L17: -O-CO-AR-O-AL-CO-,
L18: -O-CO-AR-O-AL-O-CO-,
L19: -O-CO-AR-O-AL-O-AL-O-CO-,
L20: -O-CO-AR-O-AL-O-AL-O-AL-O-CO-,
L21: -S-AL-,
L22: -S-AL-O-,
L23: -S-AL-O-CO-,
L24: -S-AL-S-AL-,
L25: -S-AR-AL-.

  The polymerizable group (Q) of the general formula (DII) is determined according to the kind of the polymerization reaction. Examples of the polymerizable group (Q) are shown below.

  The polymerizable group (Q) is preferably an unsaturated polymerizable group (Q1, Q2, Q3, Q7, Q8, Q15, Q16, Q17) or an epoxy group (Q6, Q18). More preferably, it is most preferably an ethylenically unsaturated polymerizable group (Q1, Q7, Q8, Q15, Q16, Q17). In addition, although the combination of several L and Q may differ, it is preferable that it is the same.

  The liquid crystal compound used in the present invention desirably exhibits a liquid crystal phase exhibiting good monodomain properties. By making the monodomain property favorable, it is possible to effectively prevent the resulting structure from becoming a polydomain, causing an alignment defect at the boundary between domains, and scattering light. Furthermore, it is preferable to exhibit good monodomain properties because the retardation plate has a higher light transmittance.

  Examples of the liquid crystal phase exhibited by the liquid crystalline compound used in the present invention include a columnar phase and a discotic nematic phase (ND phase). Among these liquid crystal phases, a discotic nematic phase (ND phase) that exhibits good monodomain properties and can be hybrid-aligned is particularly preferable.

  The liquid crystalline compound used in the present invention is better as the anisotropic wavelength dispersion is smaller. Specifically, Re (450) / Re (650) is 1.25, where Re (λ) is the retardation (in-plane retardation value (nm) of the liquid crystal layer at wavelength λ) that the liquid crystalline compound develops. Is preferably less than 1.20, more preferably 1.20 or less, and particularly preferably 1.15 or less.

(2) Rod-like liquid crystal compound Examples of the rod-like liquid crystal compound that can be used as the liquid crystal compound in the present invention include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, phenyl cyclohexanecarboxylate. Esters include cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles. Further, as the rod-like liquid crystal compound, not only the above low molecular liquid crystal compound but also a polymer liquid crystal compound can be used.

  In the optically anisotropic layer, the rod-like liquid crystalline molecules are preferably fixed in an aligned state, and most preferably fixed by a polymerization reaction. Examples of polymerizable rod-like liquid crystalline compounds that can be used in the present invention are described in, for example, Makromol. Chem. 190, 2255 (1989), Advanced Materials 5, 107 (1993), U.S. Pat. Nos. 4,683,327, 5,622,648, 5,770, No. 107 specification, International Publication No. 95/22586 pamphlet, No. 95/24455 pamphlet, No. 97/00600 pamphlet, No. 98/23580 pamphlet, No. 98/52905 pamphlet, JP-A-1-272551, No. 6-16616, No. 7-110469, No. 11-80081, and JP-A No. 2001-328773.

A rod-like liquid crystal compound can also be used for the optically anisotropic layer made of the liquid crystal composition.
In the case of using a rod-like liquid crystal compound, it is preferable to use two or more kinds of rod-like liquid crystal compounds in order to satisfy the characteristics required for the optically anisotropic layer made of the liquid crystal composition. Preferable combinations include a combination of at least one rod-like liquid crystal represented by the following general formula (1) and at least one rod-like liquid crystal represented by the following general formula (2).

In the general formulas (1) and (2), A and B each represent an aromatic or aliphatic hydrocarbon ring or a heterocyclic group; R ^{101 to} R ¹⁰⁴ are each a substituted or unsubstituted C 1 Represents an alkoxy group, acyloxy group, alkoxycarbonyl group or alkoxycarbonyloxy group containing an alkylene group of ˜12 (preferably C3-7) or a C1-12 (preferably C3-7) alkylene chain; R ^a , R ^b and R ^c each represents a substituent; x, y and z each represents an integer of 1 to 4;

In the general formula (1), the alkyl chain contained in R ^{101 to} R ¹⁰⁴ may be linear or branched. More preferably, it is linear. In order to cure the composition, R ^{101 to} R ¹⁰⁴ preferably have a polymerizable group at the terminal. Examples of the polymerizable group include an acryloyl group, a methacryloyl group, and an epoxy group. included.

In the general formula (1), x and z are preferably 0 and y is preferably 1, and one R ^b is a substituent in a meta position or an ortho position with respect to an oxycarbonyl group or an acyloxy group. Preferably there is. R ^b is preferably a C1-12 alkyl group (for example, a methyl group), a halogen atom (for example, a fluorine atom), or the like.

  In the general formula (2), each of A and B is preferably a phenylene group or a cyclohexylene group, and both A and B are phenylene groups, or one is a cyclohexylene group and the other is A phenylene group is preferred.

(Surface treatment of the cellulose acylate film)
The cellulose acylate film is preferably subjected to a surface treatment.
The cellulose acylate film can be appropriately surface-treated to improve adhesion with each functional layer (for example, undercoat layer, back layer, optically anisotropic layer). The surface treatment includes glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, saponification treatment (acid saponification treatment, alkali saponification treatment), and glow discharge treatment and alkali saponification treatment are particularly preferable. The “glow discharge treatment” here is a treatment for subjecting the film surface to a plasma treatment in the presence of a plasma-excitable gas. The details of these surface treatment methods are described in the Japan Institute of Invention Disclosure Technical Bulletin (Public Technical No. 2001-1745, issued on March 15, 2001, Japan Institute of Invention) and can be used as appropriate.

  In order to improve the adhesion between the film surface and the functional layer, in addition to the surface treatment or in place of the surface treatment, on the cellulose acylate film, as described in JP-A-7-333433, A coating layer (adhesive layer) can also be provided. About the said undercoat, it describes in an invention association public technical bulletin (public technical number 2001-1745, March 15, 2001 issue, invention association) 32 pages, These can be used suitably. In addition, the functional layer provided on the cellulose acylate film is described in Invention Technical Disclosure Bulletin (Public Technical No. 2001-1745, published on March 15, 2001, Invention Association), pages 32 to 45. Can be used on the cellulose acylate film as appropriate.

From the viewpoint of maintaining the flatness of the film, in these treatments, the temperature of the cellulose acylate film is preferably Tg (glass transition temperature) or lower, specifically 150 ° C. or lower.
When used as a transparent protective film for a polarizing plate, it is particularly preferable to carry out acid treatment or alkali treatment, that is, saponification treatment for cellulose acylate, from the viewpoint of adhesiveness to the polarizing film. Hereinafter, the alkali saponification treatment will be specifically described as an example.

The alkali saponification treatment is preferably performed in a cycle in which the surface of the cellulose acylate film is immersed in an alkali solution, neutralized with an acidic solution, washed with water and dried.
Examples of the alkaline solution include potassium hydroxide solution and sodium hydroxide solution. The specified concentration of hydroxide ions in the alkaline solution is preferably in the range of 0.1 to 3.0N, and more preferably in the range of 0.5 to 2.0N. The temperature of the alkaline solution is preferably in the range of room temperature to 90 ° C, and more preferably in the range of 40 to 70 ° C.

The surface energy of the cellulose acylate film after the surface treatment is preferably 55 mN / m or more, and more preferably 60 m to 75 mN / m.
The surface energy of a solid can be determined by a contact angle method, a wet heat method, and an adsorption method as described in “Basics and Applications of Wetting” (issued by Realize 1989.12.10). In the case of the cellulose acylate film, it is preferable to use a contact angle method.
Specifically, two types of solutions having known surface energies are dropped on the cellulose acylate film, and at the intersection of the surface of the droplet and the film surface, the angle formed between the tangent line drawn on the droplet and the film surface. The surface angle of the film can be calculated by defining the angle containing the droplet as the contact angle.

(Formation of alignment film)
The alignment film has a function of defining the alignment direction of the liquid crystalline compound. The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known. In the method for producing a cellulose acylate film of the present invention, the alignment film is formed by a rubbing treatment of a polymer. As the material of the alignment film, in order to set the average tilt angle on the alignment film side of the optically anisotropic layer to a desired value, in addition to polyvinyl alcohol, modified polyvinyl alcohol, polyimide, modified polyimide, acrylate monomer, methacrylate monomer, polystyrene However, it is not limited to the above range as long as a desired average tilt angle can be achieved. For example, it is preferable to use a copolymer compound described in paragraph Nos. [0014] to [0016] of JP-A-2002-98836, particularly described in [0024] to [0029] and [0173] to [0180]. It is more preferable to use a copolymer compound from the viewpoint of improving the fine orientation axis distribution of the optically anisotropic layer. Further, it is preferable to use the copolymer compound described in paragraph Nos. [0007] to [0012] of JP-A-2005-99228, and in particular, the use of the copolymer compound described in [0016] to [0020] is a fine alignment axis. It is more preferable from the viewpoint of improving the distribution. In the copolymer compounds described in the above two publications, the constitutional unit of each copolymer may be substituted with a polymerizable group such as a vinyl group from the viewpoint of improving the adhesion between the alignment film and the optically anisotropic layer. Further preferred.

The Re of the optically anisotropic layer is preferably less than 60 nm, and more preferably 55 to 20 nm.
The optically anisotropic layer is made of a liquid crystal composition with hybrid alignment. Hybrid alignment in which the average tilt angle of the liquid crystal molecules on the alignment film side is larger than the average tilt angle of the liquid crystal molecules on the opposite side is particularly preferable. The liquid crystal molecules on the alignment film surface side are preferably tilted by 45 ° or more (average tilt angle is 45 ° or more). When tilted by 50 ° or more, the stability of the rubbing azimuth angle against the azimuth regulating force increases. In terms of improving the fine orientation axis distribution, it is more preferable. On the other hand, the DLC molecules opposite to the alignment film surface side preferably have an inclination of 45 ° or less (the average tilt angle is 45 ° or less). If the inclination is 40 ° or less, the hybrid alignment is stably formed. More preferably, oblique incidence can be compensated more accurately and a higher viewing angle CR can be provided.
The state in which the discotic liquid crystal molecules are inclined by 45 ° or more means that the angle between the disc surface of the molecules and the plane direction is inclined by 45 ° or more.
Means for setting the average tilt angle of the liquid crystal molecules on the alignment film side to 45 ° or more is means for adjusting the average tilt angle to a desired range by adding an additive capable of adjusting the tilt angle in the optically anisotropic layer. Any one of a means for selecting an alignment film to bring the average tilt angle into a desired range; a means for oblique deposition, photo-alignment, etc., or a combination of two or more thereof can be carried out.
In the optically anisotropic layer made of the liquid crystal composition, there is no direction in which Re (550) is 0 nm, and the direction in which the absolute value of Re (550) is minimum is in-plane with respect to the normal direction of the layer. It is preferable that it is not present. Furthermore, it is preferably an optically anisotropic layer formed by fixing a discotic liquid crystal composition in a hybrid alignment state on the alignment film after the alignment treatment of the cellulose acylate film.
That is, it is preferable from the viewpoint of compensation of the liquid crystal cell that the optically anisotropic layer made of the liquid crystal composition contains a discotic liquid crystal compound.

When the Re (550) of the optically anisotropic layer made of the liquid crystal composition is 20 nm or more, the optical compensation ability achieved with the cellulose acylate film having the same constitution as before can be sufficiently obtained. In addition, in the case where it is less than 60 nm, there is no direction in which Re (550) is 0 nm, or in the case where the direction in which the absolute value of Re (550) is minimum is not in the normal direction or in-plane of the layer. Since the liquid crystal of the aligned cells can be sufficiently compensated, the contrast viewing angle and the color are improved, which is preferable.
The Re (550) of the optically anisotropic layer made of the liquid crystal composition is more preferably 20 to 40 nm, and particularly preferably 25 to 40 nm.

  The method for producing the optical compensation film includes a step of forming an optically anisotropic layer made of a liquid crystal composition on the surface of the cellulose acylate film on which the alignment film is formed. The optically anisotropic layer made of the liquid crystal composition is formed on the surface of the cellulose acylate film on which the alignment film is formed. Specifically, the optically anisotropic layer made of the liquid crystal composition is formed of the composition for an optically anisotropic layer made of a liquid crystal composition containing at least one liquid crystal compound, and the alignment film of the cellulose acylate film is formed. Preferably, the liquid crystal compound molecules are arranged in a desired alignment state, cured by polymerization, and fixed in the alignment state. Furthermore, there is no direction in which Re (550) is 0 nm, and there is no direction in which the absolute value of Re (550) is minimum, neither in the normal direction of the layer nor in the plane. In order to satisfy the characteristics required for the anisotropic layer, it is more preferable to fix the molecules of the liquid crystal compound (including both rod-like and disk-like molecules) in a hybrid alignment state. Hybrid alignment refers to an alignment state in which the director direction of liquid crystal molecules continuously changes in the layer thickness direction. In the case of a rod-like molecule, the director is in the major axis direction, and in the case of a disc-like molecule, the director is in the normal direction of the disc surface.

In order to bring the molecules of the liquid crystal compound into a desired alignment state, and to improve the applicability or curability of the liquid crystal composition, the composition may contain one or more additives.
In order to hybrid-align the molecules of the liquid crystal compound (particularly rod-shaped liquid crystal compound), an additive capable of controlling the orientation of the layer on the air interface side (hereinafter referred to as “air interface orientation control agent”) may be added. Examples of the additive include low molecular weight or high molecular weight compounds having a hydrophilic group such as a fluorinated alkyl group and a sulfonyl group. Specific examples of usable air interface orientation control agents include compounds described in JP-A 2006-267171.

  Further, when the liquid crystal composition is prepared as a coating liquid and an optically anisotropic layer made of the liquid crystal composition is formed by coating, a surfactant may be added to improve the coating property. As the surfactant, a fluorine-based compound is preferable, and specific examples include compounds described in paragraph numbers [0028] to [0056] in JP-A-2001-330725. Commercially available “Megafac F780” (manufactured by Dainippon Ink) may also be used.

  In addition, exemplified compounds described in paragraph numbers [0010] to [0016] and [0042] to [0063] of JP-A-2006-11350, and paragraph numbers [0209] to [0] of JP-A-2006-195140. [0238] The tilt angle on the alignment film side can be adjusted by adding the exemplified compounds described in [0238].

The liquid crystal composition preferably contains a polymerization initiator. The polymerization initiator may be a thermal polymerization initiator or a photopolymerization initiator, but a photopolymerization initiator is preferable from the viewpoint of easy control. Examples of photopolymerization initiators that generate radicals by the action of light include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670) and acyloin ethers (described in US Pat. No. 2,448,828). ), Α-hydrocarbon substituted aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), triarylimidazole dimers and p-amino Combination with phenyl ketone (described in US Pat. No. 3,549,367), acridine and phenazine compound (described in JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compound (US Pat. No. 4,221,970) Description), acetopheno Preference is given to thione compounds, benzoin ether compounds, benzyl compounds, benzophenone compounds, thioxanthone compounds and the like. Examples of the acetophenone compound include 2,2-diethoxyacetophenone, 2-hydroxymethyl-1-phenylpropan-1-one, 4′-isopropyl-2-hydroxy-2-methyl-propiophenone, 2-hydroxy -2-methyl-propiophenone, p-dimethylaminoacetone, p-tert-butyldichloroacetophenone, p-tert-butyltrichloroacetophenone, p-azidobenzalacetophenone and the like. Examples of the benzyl compound include benzyl, benzyl dimethyl ketal, benzyl-β-methoxyethyl acetal, 1-hydroxycyclohexyl phenyl ketone and the like. Examples of the benzoin ether compounds include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin-n-propyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, and benzoin isobutyl ether. Examples of the benzophenone compounds include benzophenone, methyl o-benzoylbenzoate, Michler's ketone, 4,4′-bisdiethylaminobenzophenone, 4,4′-dichlorobenzophenone, and the like. Examples of the thioxanthone compound include thioxanthone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, and the like. Among such photosensitive radical polymerization initiators composed of aromatic ketones, acetophenone compounds and benzyl compounds are particularly preferable in terms of curing characteristics, storage stability, odor, and the like. The photosensitive radical polymerization initiators composed of these aromatic ketones can be used alone or in combination of two or more according to the desired performance.
In addition to a polymerization initiator, a sensitizer may be used for the purpose of increasing sensitivity. Examples of the sensitizer include n-butylamine, triethylamine, tri-n-butylphosphine, thioxanthone and the like.

  Multiple photopolymerization initiators may be combined, and the amount used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution. The light irradiation for the polymerization of the liquid crystal compound preferably uses ultraviolet rays.

In addition to the polymerizable liquid crystal compound, the liquid crystal composition may contain a non-liquid crystalline polymerizable monomer. As the polymerizable monomer, a compound having a vinyl group, a vinyloxy group, an acryloyl group or a methacryloyl group is preferable. Note that it is preferable to use a polyfunctional monomer having two or more polymerizable reactive functional groups, for example, ethylene oxide-modified trimethylolpropane acrylate because durability is improved.
Since the non-liquid crystalline polymerizable monomer is a non-liquid crystalline component, the addition amount thereof does not exceed 15% by mass with respect to the liquid crystal compound, and is preferably about 0 to 10% by mass.

The optically anisotropic layer made of the liquid crystal composition is prepared by using the liquid crystal composition as a coating liquid, and coating the coating liquid on, for example, the surface on the alignment film side of the cellulose acylate film serving as a support. It can be formed by drying, removing the solvent, orienting the molecules of the liquid crystal compound, and then curing by polymerization. As an example of the alignment film that can be used, the polymer exemplified in the formation of the alignment film can be used, and examples thereof include a polyvinyl alcohol film and a polyimide film.
Known coating methods include curtain coating, dip coating, spin coating, print coating, spray coating, slot coating, roll coating, slide coating, blade coating, gravure coating, and wire bar method. The coating method is mentioned.
You may heat when drying a coating film. The coating film is dried to remove the solvent, and at the same time, the molecules of the liquid crystal compound in the coating film are aligned to obtain a desired alignment state.

Next, polymerization is advanced by ultraviolet irradiation or the like, the alignment state is fixed, and an optically anisotropic layer made of a liquid crystal composition is formed. It is preferable to use ultraviolet rays for light irradiation for polymerization. The irradiation energy is preferably 20 mJ / cm ^{2 to} 50 J / cm ² , and more preferably 100 mJ / cm ^{2 to} 800 mJ / cm ² . In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

  One aspect in which the cellulose acylate film produced by the production method of the present invention is used in a twisted alignment mode liquid crystal display device is an aspect in which the cellulose acylate film is used as a protective film for a polarizing plate, particularly as an inner protective film. It may be used as an inner protective film and may also be used as a support for the optical compensation film. Specifically, the cellulose acylate film can be applied to a polarizing plate having at least the cellulose acylate film and a polarizing film. When the polarizing plate is incorporated in a liquid crystal display device, the cellulose acylate film is preferably disposed on the liquid crystal cell side. The surface of the cellulose acylate film and the surface of the polarizing film are preferably bonded together, and the crossing angle between the in-plane slow axis of the cellulose acylate film and the transmission axis of the polarizing film is approximately 0 degrees. It is preferable to bond them together. There is no need to be strictly 0 degrees, and an error of about ± 5 degrees that is allowed in manufacturing does not affect the effect of the present invention and is allowed. Moreover, it is preferable that a protective film such as a cellulose acylate film is bonded to the other surface of the polarizing film.

(Polarizing film)
Examples of the polarizing film include an iodine-based polarizing film, a dye-based polarizing film using a dichroic dye, and a polyene-based polarizing film, and any of them may be used in the present invention. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film.

(Protective film)
It is preferable to use a transparent polymer film for the protective film bonded to the other surface of the polarizing film. “Transparent” means that the light transmittance is 80% or more. As the protective film, a cellulose acylate film and a polyolefin film containing polyolefin are preferable. Among the cellulose acylate films, a cellulose triacetate film is preferable. Of the polyolefin films, a polynorbornene film containing a cyclic polyolefin is preferable.
The thickness of the protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm.

(Light diffusion film)
The polarizing plate may have a light diffusion film on one surface of the polarizing film. The light diffusion non-film may be a single layer film or a laminated film. As an example of the aspect of a laminated | multilayer film, the light-diffusion film which has a light-scattering layer on the light transmissive polymer film is mentioned. The light diffusing film contributes to the improvement of the viewing angle when the viewing angle is inclined in the vertical and horizontal directions, and has a particularly high effect in an aspect in which an antireflection layer is disposed outside the polarizing film on the display surface side. The light diffusion film (or its light scattering layer) can be formed from a composition in which fine particles are dispersed in a binder. The fine particles may be inorganic fine particles or organic fine particles. The binder and the fine particles preferably have a refractive index difference of about 0.02 to 0.20. Further, the light diffusion film (or the light scattering layer thereof) may have a hard coat function. As for the light diffusion film that can be used in the present invention, for example, Japanese Patent Application Laid-Open No. 11-38208 with a specified light scattering coefficient, Japanese Patent Application Laid-Open No. 2000-199809 with a relative refractive index of transparent resin and fine particles as a specific range, JP-A No. 2002-107512, etc., in which the haze value is defined as 40% or more.

(Hard coat film, antiglare film, antireflection film)
In some cases, the cellulose acylate film may be applied to a hard coat film, an antiglare film, and an antireflection film. For the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, etc., any or all of a hard coat layer, an antiglare layer and an antireflection layer are provided on one or both sides of the cellulose acylate film. be able to. Preferred embodiments of such an antiglare film and antireflection film are described in detail on pages 54 to 57 of the Japan Society for Invention and Innovation (Publication No. 2001-1745, published on March 15, 2001, Japan Society of Invention and Innovation). It can be preferably used also in the cellulose acylate film.

(Preparation method of polarizing plate)
The polarizing plate can be produced as a long polarizing plate. For example, using the cellulose acylate film, an alignment film forming coating liquid is applied to the surface of the cellulose acylate film as desired to form an alignment film, and subsequently, an optically anisotropic layer forming coating liquid comprising a liquid crystal composition An optically anisotropic layer made of a liquid crystal composition is formed by continuously coating the surface of the cellulose acylate film on the alignment film side and drying to obtain a desired alignment state, and then fixing the alignment state by light irradiation. The long retardation film can be formed and rolled up into a roll. Separately, a long polarizing film and a long polymer film for a protective film rolled up in a roll and bonded in a roll-to-roll manner can be produced as a long polarizing plate. . The long polarizing plate is, for example, transported and stored in a roll-up state, and cut into a predetermined size when incorporated into a liquid crystal display device. In addition, the said polarizing plate does not need to be elongate and the preparation method described here is only an example.
When producing the cellulose acylate film, if it is stretched in the direction perpendicular to the film transport direction, roll-to-roll processing is possible at the time of polarizing plate creation, simplification of the process, and the axis of the polarizing film. It is preferable because improvement in bonding accuracy can be achieved.
A polarizing plate used in a vertical alignment mode liquid crystal display device to be described later may not include an optically anisotropic layer and an alignment film formed in the polarizing plate used in the twisted alignment mode liquid crystal display device.

FIG. 1 shows a schematic cross-sectional view of an example of a twisted alignment mode liquid crystal display device having a cellulose acylate film produced by the production method of the present invention.
The liquid crystal display device shown in FIG. 1 includes a liquid crystal cell 10 of a twisted alignment mode such as a TN mode, and elliptically polarizing plates 22a and 22b above and below the liquid crystal cell 10, respectively. The elliptically polarizing plates 22a and 22b have linearly polarizing films 18a and 18b, and further have optically anisotropic layers 12a and 12b made of a liquid crystal composition, and cellulose acylate films 14a and 14b that are support bodies thereof. It has optical compensation films 16a and 16b. The optically anisotropic layers 12a and 12b have an action of optically compensating for birefringence generated in an oblique direction due to the liquid crystal molecules in the twisted alignment mode liquid crystal cell 10 being inclined and aligned near the substrate surface. From this point of view, it is preferable to contain a discotic liquid crystal compound fixed in a hybrid alignment state. Cellulose acylate films 14a and 14b are films produced by the production method of the present invention, are films exhibiting high Re and high Rth, and share Rth which is insufficient only in optically anisotropic layers 12a and 12b. Contributes to optical compensation.

  The cellulose acylate films 14a and 14b are also used as protective films for the polarizers 18a and 18b, respectively. The absorption axes of the linearly polarizing films 18a and 18b are arranged so as to be orthogonal to each other. The in-plane slow axes of the cellulose acylate films 14a and 14b are orthogonal to the absorption axes of the linearly polarizing films 18a and 18b arranged closer to each other. Outer protective films 20a and 20b are disposed on the outer sides of the linear polarizing films 18a and 18b, respectively. The outer protective films 20a and 20b may be cellulose acylate films produced by the production method of the present invention, or may be other films. Since it does not participate in optical compensation, it will be selected from various polymer films in view of durability and cost.

In the TN mode liquid crystal cell used in the present invention, it is preferable that color filters having different transmission main wavelengths are formed on the inner surface of the cell substrate so as to correspond to at least three pixel regions. The picture element region is preferably composed of three picture element regions of R, G, and B. In the present invention, it is preferable that the thickness of the liquid crystal layer corresponding to each picture element region is different in at least two picture element regions in order to suppress a yellowish change in the left-right direction. The preferred thickness of the liquid crystal layer in each pixel area varies depending on Δnd of the liquid crystal cell, wavelength dispersion of the liquid crystal, color filter transmittance, etc., but the relationship of B picture element thickness ≦ G picture element thickness ≦ R picture element thickness It is preferable that Further, d _B (B picture element thickness) / d _R (R picture element thickness) is preferably 0.95 or less, more preferably 0.9 or less, and 0.8 or less. Further preferred. Although adjustment of the thickness of a liquid crystal layer is not specifically limited, For example, the thickness of a corresponding liquid crystal layer can be changed by changing the thickness of the color filter of each color. In addition, the ratio of Δnd between B and R pixels by adjusting the thickness of the liquid crystal layer, Δnd _B (wavelength 450 nm) / Δnd _R (wavelength 630 nm) is preferably 1.05 or less, and 1.0 or less. More preferably, it is 0.9 or less.

Cellulose acylate film for vertical alignment mode liquid crystal display:
The cellulose acylate film produced by the production method of the present invention is used as an optical compensation film or as a protective film for a polarizing plate (preferably an inner protective film disposed on the liquid crystal cell side), such as a vertical VA mode. It can be used for an alignment mode liquid crystal display device. The cellulose acylate film used in the vertical alignment mode liquid crystal display device preferably has a high Re and a high Rth, and preferably has Re of 5 to 50 nm and Rth of 90 to 150 nm.

FIG. 2 shows a schematic cross-sectional view of an example of a vertical alignment mode liquid crystal display device having a cellulose acylate film produced by the production method of the present invention.
The liquid crystal display device shown in FIG. 2 includes a vertical alignment mode liquid crystal cell 10 ′ such as a VA mode, and elliptically polarizing plates 22a ′ and 22b ′ above and below the liquid crystal cell 10 ′. The elliptically polarizing plates 22a ′ and 22b ′ have linear polarizing films 18a and 18b, and further have cellulose acylate films 14a ′ and 14b ′ as inner protective films, respectively. The cellulose acylate films 14a ′ and 14b ′ are films produced by the production method of the present invention, and are films exhibiting high Re and high Rth. The cellulose acylate films 14a ′ and 14b ′ contribute to reducing light leakage during black display caused by the relationship between the absorption axes of the linearly polarizing films 18a and 18b deviating from the orthogonal relationship in the oblique direction.

  The cellulose acylate films 14a 'and 14b' are also used as protective films for the polarizers 18a and 18b, respectively. The absorption axes of the linearly polarizing films 18a and 18b are arranged so as to be orthogonal to each other. The in-plane slow axes of the cellulose acylate films 14a 'and 14b' are orthogonal to the absorption axes of the linearly polarizing films 18a and 18b disposed closer to each other. Outer protective films 20a and 20b are disposed on the outer sides of the linear polarizing films 18a and 18b, respectively. The outer protective films 20a and 20b may be cellulose acylate films produced by the production method of the present invention, or may be other films. Since the outer protective films 20a and 20b are not involved in optical compensation, they may be selected from various polymer films from the viewpoint of durability and cost.

  The features of the present invention will be described more specifically with reference to examples and comparative examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below.

<Measurement method>
First, measurement methods and evaluation methods of characteristics used in Examples and Comparative Examples are shown below.
(1) Degree of substitution The degree of acyl substitution of cellulose acylate was determined by ¹³ C-NMR by the method described in Carbohydr. Res. 273 (1995) 83-91 (Tezuka et al.).

(2) Heat of crystallization (ΔHc)
Using a DSC measuring apparatus (DSC8230: manufactured by Rigaku Corporation), 5-6 mg of a cellulose acylate film was placed in a DSC aluminum measuring pan (Cat. No. 8578: manufactured by Rigaku Corporation), and this was 50 mL / min. The temperature was raised from 25 ° C. to 120 ° C. at a rate of 20 ° C./min and held for 15 minutes, then cooled to 30 ° C. at −20 ° C./min. The area surrounded by the exothermic peak that appeared when the temperature was raised to 320 ° C. at a rate of temperature increase of 20 ° C./min and the baseline of the sample was defined as the crystallization heat of the cellulose acylate film.

1. Preparation of Cellulose Acylate Film (1-1) Preparation of Dope Cellulose acetate solutions containing the compositions shown in the table below and oligomers having number average molecular weights in the addition amounts shown in the table below were prepared.
――――――――――――――――――――――――――――――――――――――
Composition of cellulose acetate solution ――――――――――――――――――――――――――――――――――――――
-Cellulose acetate with an average substitution degree of 2.86 100.0 parts by mass-Methylene chloride (first solvent) 475.9 parts by mass-Methanol (second solvent) 113.0 parts by mass-Butanol (third solvent) 5.9 0.13 parts by mass of silica particles having an average particle size of 16 nm (AEROSIL R972, manufactured by Nippon Aerosil Co., Ltd.)
・ Oligomer (Composition is shown in the table below) Shown in the table below ――――――――――――――――――――――――――――――――――― -

Each of the prepared solutions was cast on a mirror stainless steel support, which is a drum having a diameter of 3 m, through a cast Giuser under the PIT draw conditions shown in the following table.
Next, when the residual solvent amount and the film surface temperature of the web on the support reached the values shown in the following table, the webs were each stretched in the TD direction at the stretching ratios shown in the following table. In the stretching process, the web was stretched in the TD direction by gripping both ends of the web with a pin-shaped tenter and spreading the web in a direction perpendicular to the conveying direction.
After stretching, when the amount of residual solvent of the web reached the value shown in the following table, the web was heat treated at the film surface temperature shown in the following table. The heat treatment was performed by controlling the temperature of the drying zone with the drying air. Moreover, heat processing was performed on the conditions which fixed the pin-shaped tenter.

  The following table shows the production conditions of each film and the optical properties of each film. In addition, Re in the table is expressed by adding the direction orthogonal to the casting direction as a plus.

From the results shown in the above table, the cellulose acylate films of Examples 1 to 12 produced by the production method of the present invention have twisted alignment mode liquid crystals exhibiting optical characteristics with Re of 5 to 20 nm and Rth of 90 to 150 nm. It can be understood that the film is useful for an optical film for a display device. In Examples 10 and 11, it can be understood that the film is useful for an optical film for a vertical alignment mode liquid crystal display device having optical characteristics of Re of 5 to 50 nm and Rth of 90 to 150 nm.
On the other hand, the cellulose acylate films of Comparative Examples 1 and 2 produced under the same conditions as in Example 2 using an oligomer that does not contain an aromatic group or a non-oligomer as a plasticizer, exhibited both Re and Rth. Therefore, the optical film for twisted alignment mode and vertical alignment mode liquid crystal display devices was not suitable.
Similarly, in Comparative Example 3 in which an aromatic group-containing oligomer is used as a plasticizer but is not heat-treated at a temperature sufficient to increase the degree of orientation of the oligomer, the twisted alignment mode and vertical alignment mode liquid crystal displays are similarly applied. As an optical film for an apparatus, a cellulose acylate film having suitable characteristics could not be obtained.

2. Production of TN mode liquid crystal display device (2) -1 Saponification treatment of cellulose acylate film For each of cellulose acylate films Examples 1 to 6, 8, and 9 obtained above, a dielectric heating roll having a temperature of 60 ° C was applied. After passing the film and raising the film surface temperature to 40 ° C., an alkaline solution having the composition shown below was applied at 14 ml / m ² using a bar coater and heated to 110 ° C. The product was retained for 10 seconds under Noritake Co.), and then 3 ml / m ^{2 of} pure water was applied using the same bar coater. The film temperature at this time was 40 degreeC. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then the film was retained in a drying zone at 70 ° C. for 2 seconds and dried. ────────────────────────────────────
Composition of alkaline solution for saponification treatment────────────────────────────────────
Potassium hydroxide 4.7 parts by weight of water 15.7 parts by mass Isopropanol 64.8 parts by mass Propylene glycol 14.9 parts by mass Surfactant _{(C 16 H 33 O (CH} 2 CH 2 0) 10 H ) 1.0 part by mass ─────────────────────────────────────

(2) -2 saponified surface of the forming saponified cellulose acylate film of the alignment film, an alignment film-forming coating solution having the following composition with a wire bar coater of # 14 24 ml / m ² was applied, the 100 ° C. temperature Dry with wind for 120 seconds. The thickness of the alignment film was 1.2 μm. Next, the longitudinal direction (conveying direction) of the film was set to 0 °, and a rubbing treatment having a width of 2000 mm was used for the formed alignment film, and the rubbing treatment was performed in the 0 ° direction at a rotation speed of the rubbing roller of 400 rpm. At this time, the conveyance speed was 40 m / min. Subsequently, the rubbing surface was subjected to ultrasonic dust removal.
――――――――――――――――――――――――――――――――――――――
Composition of coating solution for alignment film formation ――――――――――――――――――――――――――――――――――――――――
-Denatured polyvinyl alcohol 40 parts by weight-728 parts by weight of water-228 parts by weight of methanol-2 parts by weight of glutaraldehyde (crosslinking agent)-0.69 parts by weight of citric acid ester (AS3, Sankyo Chemical Co., Ltd.) ―――――――――――――――――――――――――――――――――――

(2) -3 Formation of optically anisotropic layer An optically anisotropic layer coating solution having the composition shown in the following table was applied to the rubbing-treated surface of the alignment film after dust removal using a wire bar. Then, it heated for 120 second in a 130 degreeC thermostat, and the discotic liquid crystal compound was orientated. Next, using a 160 W / cm high-pressure mercury lamp at 80 ° C., UV irradiation was performed for 40 seconds to advance the crosslinking reaction, thereby polymerizing the discotic liquid crystal compound. Then, it stood to cool to room temperature.
Re of the obtained optically anisotropic layer alone measured at a wavelength of 550 nm was 45 nm. The film thickness of the optically anisotropic layer alone is shown in the following table. Further, in the first optically anisotropic layer, the discotic liquid crystal compound molecules are fixed in a hybrid alignment state, there is no direction in which Re (550) is 0 nm, and the absolute value of Re (550) The direction in which the value is minimum is neither in the normal direction nor in the plane of the layer, so that the wavelength is 550 nm from each inclined direction in 10 degree steps from the normal direction to 50 degrees on one side with respect to the film normal direction. In total, 11 points were measured, and the measured retardation value, assumed value of average refractive index, and input film thickness value were confirmed from KOBRA 21ADH. Similarly, the inclination angle of the disc surface of the discotic liquid crystal compound in the optically anisotropic layer was measured using KOBRA 21ADH. In this case, the upper tilt angle represents the air interface side, and the lower tilt angle represents the alignment film side interface.

――――――――――――――――――――――――――――――――――――――
Composition of coating solution for optically anisotropic layer formation ――――――――――――――――――――――――――――――――――――――
-270 parts by mass of methyl ethyl ketone-90 parts by mass of the first liquid crystalline compound shown in the following table (liquid crystal composition)-10 parts by mass of the second liquid crystalline compound shown in the following table (liquid crystal composition)-An air interface alignment controller having the following structure. 0 parts by mass / photoinitiator Irgacure 907 Ciba Japan Co., Ltd. 3.0 parts by mass Sensitizer Kayacure DETX Nippon Kayaku 1.0 parts by mass ――――――――――――― ――――――――――――――――――――――――

  In this way, optical compensation films 21 to 28 were produced. The types of the cellulose acylate film used as a support for the production of these optical compensation films and the liquid crystal compounds used for the formation of the optically anisotropic layer are summarized in the following table.

(2) -4 Production of Optical Compensation Film 29 On the cellulose acylate film produced in Example 7, an optical anisotropic layer was formed by the following method to produce an optical compensation sheet 29.
Saponification treatment of cellulose acylate film:
The cellulose acylate film obtained above was passed through a dielectric heating roll having a temperature of 60 ° C., and the film surface temperature was raised to 40 ° C., and then an alkaline solution having the composition shown below was 14 ml / m using a bar coater. ^The coating was carried out at ² and kept for 10 seconds under a steam far infrared heater (manufactured by Noritake Co., Ltd.) heated to 110 ° C., and then 3 ml / m ^{2 of} pure water was applied using the same bar coater. The film temperature at this time was 40 degreeC. Next, washing with a fountain coater and draining with an air knife were repeated three times, and then the film was retained in a drying zone at 70 ° C. for 2 seconds and dried.

────────────────────────────────────
Composition of alkaline solution for saponification treatment────────────────────────────────────
Potassium hydroxide 4.7 parts by weight of water 15.7 parts by mass Isopropanol 64.8 parts by mass Propylene glycol 14.9 parts by mass Surfactant _{(C 16 H 33 O (CH} 2 CH 2 O) 10 H ) 1.0 part by mass ─────────────────────────────────────

Formation of alignment film:
On the saponified surface of the saponified cellulose acylate film, a coating solution for forming an alignment film having the following composition was applied with a # 14 wire bar coater at 24 ml / m ² and dried with hot air at 100 ° C. for 120 seconds. The thickness of the alignment film was 1.2 μm. Next, the longitudinal direction (conveying direction) of the film was set to 0 °, and a rubbing treatment having a width of 2000 mm was used for the formed alignment film, and the rubbing treatment was performed in the 0 ° direction at a rotation speed of the rubbing roller of 400 rpm. At this time, the conveyance speed was 40 m / min. Subsequently, the rubbing surface was subjected to ultrasonic dust removal.

―――――――――――――――――――――――――――――――――――――
Composition of coating solution for alignment film formation ―――――――――――――――――――――――――――――――――――――
-Alignment film polymer 40 parts by weight-Water 700 parts by weight-Methanol 300 parts by weight-Triethylamine 20 parts by weight-------------- ――――――――――――

Formation of optically anisotropic layer:
A coating liquid for optically anisotropic layer having the composition shown in the following table was applied to the rubbing-treated surface of the alignment film after dust removal using a wire bar. Then, it heated for 120 second in a 130 degreeC thermostat, and the discotic liquid crystal compound was orientated. Next, using a 160 W / cm high-pressure mercury lamp at 80 ° C., UV irradiation was performed for 40 seconds to advance the crosslinking reaction, thereby polymerizing the discotic liquid crystal compound. Then, it stood to cool to room temperature.
――――――――――――――――――――――――――――――――――――――
Composition of coating solution for optically anisotropic layer formation ――――――――――――――――――――――――――――――――――――――
-270 parts by mass of methyl ethyl ketone-100 parts by mass of the discotic liquid crystalline compound of A1 below-1.0 part by mass of the air interface alignment controller of B1 below-photoinitiator Irgacure 907 3.0 parts by mass of Ciba Japan Co., Ltd.- Sensitizer KayaCure DETX Nippon Kayaku 1.0 parts by mass ―――――――――――――――――――――――――――――――――――― -

  The obtained optically anisotropic layer had a thickness of 1 μm, and an upper tilt angle and a lower tilt angle were 20 degrees and 70 degrees, respectively.

(2) -5 Production of Polarizing Plate A polyvinyl alcohol (PVA) film having a thickness of 80 μm is dyed by dipping in an aqueous iodine solution having an iodine concentration of 0.05 mass% at 30 ° C. for 60 seconds, and then boric acid concentration is 4 mass. The film was longitudinally stretched 5 times the original length while immersed in an aqueous boric acid solution of% concentration for 60 seconds, and then dried at 50 ° C. for 4 minutes to obtain a polarizing film having a thickness of 20 μm.
Each of the produced optical compensation films 21 to 29 has an exposed surface on the cellulose acylate film side (a surface on which the optically anisotropic layer made of the liquid crystal composition is not formed) of 1.5 mol / L of 55 ° C. water. After dipping in an aqueous sodium oxide solution, the sodium hydroxide was thoroughly washed away with water. Then, after dipping for 1 minute in a 35 ° C. dilute sulfuric acid aqueous solution at 0.005 mol / L, the dilute sulfuric acid aqueous solution was sufficiently washed away by water and finally sufficiently dried at 120 ° C.
The film subjected to the saponification treatment as described above is combined with a commercially available cellulose acetate film subjected to the same saponification treatment, and the saponification treatment surface is bonded using a polyvinyl alcohol adhesive so as to sandwich the polarizing film. Thus, a polarizing plate was obtained. Here, Fujitac TF80UL (manufactured by FUJIFILM Corporation) was used as a commercially available cellulose acetate film. At this time, since the polarizing film and the protective films on both sides of the polarizing film were produced in the form of rolls, the longitudinal directions of the roll films were parallel to each other and were bonded together. Therefore, the longitudinal direction of the film (film casting direction) and the absorption axis of the polarizing film were parallel to each other.
Polarizing plates 31 to 39 each having optical compensation films 21 to 29 were produced.

(2) -6 Production of TN mode liquid crystal display device A TN mode liquid crystal display device having the same structure as that of FIG. 1 was produced. Specifically, a pair of polarizing plates provided in a liquid crystal display device (AL2216W, manufactured by Nippon Acer Co., Ltd.) using a TN mode liquid crystal cell is peeled off, and the above-prepared polarizing plate is replaced with an optically anisotropic material. The adhesive layer was attached to the viewer side and the backlight side one by one so as to be on the liquid crystal cell side. At this time, the transmission axis of the polarizing plate on the observer side and the transmission axis of the polarizing plate on the backlight side were arranged so as to be orthogonal to each other. In this manner, TN mode liquid crystal display devices 101 to 109 were produced.

3. Production of VA mode liquid crystal display device (3) -1 Production of polarizing plate for VA A polyvinyl alcohol (PVA) film having a thickness of 80 μm was immersed in an aqueous iodine solution having an iodine concentration of 0.05 mass% at 30 ° C. for 60 seconds. After being dyed and then immersed in a boric acid aqueous solution having a boric acid concentration of 4% by weight for 60 seconds, the film was longitudinally stretched 5 times the original length and then dried at 50 ° C. for 4 minutes to a thickness of 20 μm. A polarizing film was obtained.
TD80 (manufactured by FUJIFILM Corporation), which is a commercially available triacetyl cellulose film, was immersed in an aqueous sodium hydroxide solution (concentration: 1.5 mol / L) at 55 ° C., and then sufficiently washed with water. Washed away. Then, after being immersed for 1 minute in 35 degreeC dilute sulfuric acid aqueous solution (concentration 0.005 mol / L), it was immersed in water and the dilute sulfuric acid aqueous solution was fully washed away. Finally, it was sufficiently dried at 120 ° C. to complete the saponification treatment.
Each of the cellulose acylate films of Example 11 produced above was similarly saponified.

  It was bonded to one surface of the produced polarizing film, and the saponification surface of the cellulose acylate film of Example 11 was bonded to the saponification surface of the triacetyl cellulose film TD80 and the opposite surface, respectively. Each plate 41 was produced.

(3) -2 Preparation of VA panel The front and back polarizing plates attached to LC-46LX1 (made by Sharp) are peeled off, and polarizing plate 41 is placed on the light source side so that the slow axis of the liquid crystal cell and the absorption axis of the rear polarizing plate are orthogonal. Then, the cellulose acylate film of Example 11 was attached with an adhesive so as to be on the liquid crystal cell side, and the polarizing plate 41 was also absorbed on the opposite side of the liquid crystal cell to the slow axis of the liquid crystal cell and the rear polarizing plate. The cellulose acylate film of Example 11 of the polarizing plate was placed on the liquid crystal cell side so that the axes were orthogonal to each other and adhered with an adhesive to produce a VA liquid crystal display device having the same configuration as in FIG.

4). Evaluation of Liquid Crystal Display Device With respect to the TN mode liquid crystal display device produced above, the viewing angle in the vertical and horizontal directions and the viewing angle in the oblique 45 degree direction were calculated for the VA mode liquid crystal display device.
Specifically, the contrast viewing angles of the black display (L1) and the white display (L8) were measured for the liquid crystal display devices manufactured in each Example using a measuring instrument (EZ-Contrast 160D, manufactured by ELDIM). The average value of the contrast ratio (white transmittance / black transmittance) was determined in the vertical and horizontal directions (TN) at a polar angle of 80 degrees or the oblique 45 degrees direction (VA). Evaluation was made according to the following criteria.
◎: 50 or more ○: Less than 50, 40 or more Δ: Less than 40, 30 or more ×: Less than 30

  As a result, an evaluation result of “◯” or more was obtained for both the TN mode and VA mode liquid crystal display devices each having the cellulose acylate film produced by the production method of the present invention. Further, the TN mode liquid crystal display devices to which the optical compensation sheets 29 and 30 produced using the cellulose acylate films of Examples 7 and 11, respectively, are applied. The cellulose acylates of Examples 1 to 6, 8, and 9 are used. Compared with a TN mode liquid crystal display device using a film, the front contrast was high, specifically 1.5 times.

5. Preparation of TN mode liquid crystal display device (5) -1 Preparation of cellulose acylate film (Example 14)
In Example 3, the cellulose acylate film of Example 14 was produced in the same manner as in Example 3, except that 3.2% by mass of the wavelength dispersion adjusting agent shown in Table 5 was further added.
Furthermore, according to the production conditions described in Tables 5 to 11 below, films of Example 13 and Examples 15 to 48 were produced. The optical properties of the obtained films are also shown in the table below. In addition, Re in the table is expressed by adding the direction orthogonal to the casting direction as a plus.
Further, Rth (450) / Rth (550) of each cellulose acylate film was measured for a thickness direction retardation (Rth (550)) at a wavelength of 550 nm and a thickness direction retardation (Rth (450)) at a wavelength of 450 nm. (450) / Rth (550) was determined.
The remaining amount of the wavelength dispersion adjusting agent was calculated by the following method.
The obtained cellulose acylate film was irradiated for 200 hours under the condition of 150 W / m ² using “Super Xenon Weather Meter SX75 (manufactured by Suga Test Instruments Co., Ltd.)”, and the residual amount of the wavelength dispersion adjusting agent was measured. . In addition, between the cellulose acylate film and the light source of the weather meter, the optical film described in paragraphs [0080] to [0082] of JP-A-2008-116788 was installed and measured. For each numerical value, the residual ratio after light irradiation was calculated by applying the following formula.
((Remaining amount of wavelength dispersion adjusting agent after light irradiation) / (Remaining amount of wavelength dispersion adjusting agent before light irradiation)) × 100

(5) -2 Saponification treatment of cellulose acylate film The cellulose acylate films of Examples 13 to 48 were respectively saponified by the same method as in (2) -1.

(5) -3 Formation of Alignment Film On the saponified surface of the saponified cellulose acylate film, a coating solution for forming an alignment film having the following composition was applied at 24 ml / m ² with a # 14 wire bar coater and heated at 100 ° C. Dry with wind for 120 seconds. The thickness of the alignment film was 1.2 μm. Next, the longitudinal direction (conveying direction) of the film was set to 0 °, and a rubbing treatment having a width of 2000 mm was used for the formed alignment film, and the rubbing treatment was performed in the 0 ° direction at a rotation speed of the rubbing roller of 400 rpm. At this time, the conveyance speed was 40 m / min. Subsequently, the rubbing surface was subjected to ultrasonic dust removal.

――――――――――――――――――――――――――――――――――――――
Composition of coating solution for alignment film formation ――――――――――――――――――――――――――――――――――――――――
・ The following modified polyvinyl alcohol: 40 parts by mass ・ Water: 728 parts by mass ・ Methanol: 228 parts by mass ―――――――――――――――――――――――――――――――― ―――――――

(5) -4 Formation of optically anisotropic layer An optically anisotropic layer coating solution having the composition shown in the following table was applied to the rubbing-treated surface of the alignment film after dust removal using a wire bar. Then, it heated for 120 second in a 130 degreeC thermostat, and the discotic liquid crystal compound was orientated. Next, using a 160 W / cm high-pressure mercury lamp at 80 ° C., UV irradiation was performed for 40 seconds to advance the crosslinking reaction, thereby polymerizing the discotic liquid crystal compound. Then, it stood to cool to room temperature.
――――――――――――――――――――――――――――――――――――――
Composition of coating solution for optically anisotropic layer formation ――――――――――――――――――――――――――――――――――――――
-270 parts by mass of methyl ethyl ketone-100 parts by mass of the following discotic liquid crystalline compound A1-1.0 part by mass of the following fluoroaliphatic group-containing polymer 1-0.5 part by mass of the alignment film side alignment controller 1 below-the following Alignment film side alignment control agent 2 1.5 parts by mass, 4-vinylphenylboronic acid 0.1 part by mass, photoinitiator Irgacure 907 Ciba Japan Co., Ltd. 3.0 parts by mass, sensitizer Kayacure DETX Nippon Chemical 1.0 parts by mass of medicinal product ――――――――――――――――――――――――――――――――――――――

The obtained optically anisotropic layer had a thickness of 1 μm, and an upper tilt angle and a lower tilt angle were 20 degrees and 65 degrees, respectively.
Thus, the optical compensation film 31 was produced, and the optical compensation films 30 and 32 to 65 were produced in the same manner as the optical compensation film 31.

(5) -5 Production of Polarizing Plate Polarizing plates 42 to 77 were produced in the same manner as in (2) -5 above.

(5) -6 Production of TN mode liquid crystal display devices TN mode liquid crystal display devices 110 to 145 were produced by the same method as in (2) -6 above.

6). Evaluation of TN Mode Liquid Crystal Display Device (6) -1 Evaluation of Viewing Angle Contrast For each of the TN mode liquid crystal display devices manufactured as described above, the contrast ratio (white transmittance / black transmittance) in the vertical and horizontal directions is the same as described above. ) Was determined and evaluated according to the following criteria.
：: 50 or more ○: Less than 50, 40 or more Δ: Less than 40, 30 or more ×: Less than 30 As a result, evaluation results of “◯” or more were obtained.

(6) -2 Evaluation with yellowishness in oblique horizontal direction About the produced liquid crystal display devices 110 to 145, the brightness was divided into eight equal parts from black to white (black display (L1) to white display (L8)), When displaying the brightness of the second level (L2) from black, the normal direction of the display surface is 0 °, and the color change Δu′v ′ (average value in the left-right direction) from 0 ° to a polar angle of 60 ° ) And the yellowness level was evaluated according to the following criteria. The results are shown in Tables 5 to 11.
A: 0.000 ≦ Δu′v ′ ≦ 0.085
○: 0.085 <Δu′v ′ ≦ 0.090
Δ: 0.090 <Δu′v ′ ≦ 0.100
×: 0.100 <Δu′v ′ ≦ 0.105

* Δu′v ′: Σ {(u ′ _n −u ′ _n−1 ) ² + (v ′ _n −v ′ _n−1 ) ² } (from 0 ° to 60 ° polar angle in 10 ° increments)

表５〜表１１中、
＊１：「ＴＰＡ」はテレフタル酸、「ＰＡ」はフタル酸、「ＡＡ」はアジピン酸、「ＳＡ」はコハク酸を意味する。
＊２：「ＥＧ」はエタンジオール、「ＰＧ」は１，３−プロパンジオールを意味する。
＊３：数平均分子量を意味する。
＊４：「ＴＰＡ」、「ＰＡ」、「ＡＡ」、「ＳＡ」、「ＥＧ」、および「ＰＧ」の単位は全てモル比を表す。
化合物１〜化合物５は、以下の構造式で示される化合物である。

In Tables 5 to 11,
* 1: “TPA” means terephthalic acid, “PA” means phthalic acid, “AA” means adipic acid, and “SA” means succinic acid.
* 2: “EG” means ethanediol and “PG” means 1,3-propanediol.
* 3: Means the number average molecular weight.
* 4: The units of “TPA”, “PA”, “AA”, “SA”, “EG”, and “PG” all represent molar ratios.
Compounds 1 to 5 are compounds represented by the following structural formulas.

From the results shown in the above table, the cellulose acylate films of Examples 13 to 48 produced by the production method of the present invention have a twisted orientation in which Re is 5 to 20 nm and Rth is 90 to 150 nm. It can be understood that the film is useful for an optical film for a mode liquid crystal display device. Further, as described above, the evaluation results of the viewing angle contrast in the vertical and horizontal directions were actually all good.
In particular, among the cellulose acylate films produced by the production method of the present invention, a cellulose acylate film satisfying 0.90 <Rth (450) / Rth (550) ≦ 1.5 is used for a TN mode liquid crystal display device. When used for optical compensation, it can be understood that yellowing that occurs in the oblique lateral direction can be significantly reduced. It can also be understood that, for adjusting the wavelength dispersion, it is effective to add a wavelength dispersion adjusting agent together with the aromatic group-containing oligomer.
In order to improve light resistance, the compound represented by the general formula (IX) (compound 2) and any one of the compounds represented by the general formulas (IX-a) to (IX-d) (compound 3, It can also be seen that mixing with compound 5) is effective.

10, 10 'Liquid crystal cell 12a, 12b Optically anisotropic layer 14a, 14a', 14b, 14b 'Inner protective film 16a, 16b of polarizing plate Optical compensation film 18a, 18b Linear polarizing film 20a, 20b Outer protective film 22a, 22b Elliptical polarizing plate

Claims (23)

A casting step of casting a liquid containing cellulose acylate, an aromatic group-containing oligomer and a solvent on a support to form a web;
A stretching step of stretching the web and orienting at least the molecules of the aromatic group-containing oligomer in the stretching direction;
A heat treatment step of heat-treating the stretched web to increase the degree of molecular orientation of at least the aromatic-containing oligomer;
A method for producing a cellulose acylate film, comprising: 2. The oligomer of claim 1, wherein the aromatic group-containing oligomer is an oligomer of a polycondensed ester containing at least one aromatic dicarboxylic acid residue and at least one aliphatic diol residue. the method of. The method according to claim 1 or 2, wherein the aromatic group-containing oligomer has a number average molecular weight of 500 to 2,000. The method according to any one of claims 1 to 3, wherein the liquid contains 3 to 20 parts by mass of the aromatic-containing oligomer with respect to 100 parts by mass of the cellulose acylate. 5. The method according to claim 1, wherein in the stretching step, a web having a residual solvent amount of 20 to 300 mass% is stretched at a film surface temperature of −30 to 80 ° C. 5. The method according to any one of claims 1 to 5, wherein in the heat treatment step, a web having a residual solvent amount of 10 to 120% by mass is heat-treated at a film surface temperature of 40 to 200 ° C. The method according to any one of claims 1 to 6, wherein in the stretching step, the web is stretched at a stretch ratio of 1 to 50%. The method according to claim 1, wherein the liquid is cast on a drum surface. The method according to claim 1, wherein in the stretching step, the web is stretched in a direction orthogonal to the casting direction. The method according to claim 1, wherein the web is not stretched after the stretching step. The method according to any one of claims 1 to 10, wherein the liquid contains 0.2 to 20% by mass of a wavelength dispersion adjusting agent having an absorption maximum at 250 to 400 nm. The method according to claim 11, wherein the wavelength dispersion adjusting agent is a merocyanine compound represented by the following general formula (IX):

In General Formula (IX), N represents a nitrogen atom, and R ^{1 to} R ⁷ each represents a hydrogen atom or a substituent. Any compound represented by the following general formula (IXa-a), (IXa-b), (IXa-c), and (IXa-d), and a merocyanine compound represented by the general formula (IX) The method according to claim 12, characterized in that a mixture thereof is used.

In general formula (IXa-a), R ^<6a> and R ^<7a> respectively represent a hydrogen atom or a substituent; In general formula (IXa-b), R ^<6b> and R ^<7b> respectively represent a hydrogen atom or a substituent; In general formula (IXa-c), R ^6C and R ^7C each represent a hydrogen atom or a substituent; in general formula (IXa-d), R ¹¹ and R ¹² represent an alkyl group, an aryl group, and cyano, respectively. Represents a group, or —COOR ¹³ , or represents a ring containing a nitrogen atom bonded to each other; R ¹³ represents an alkyl group, an aryl group, or a heterocyclic group; Furthermore, the method of any one of Claims 1-13 characterized by containing the triazine type compound represented by the following general formula (II);

In general formula (II), X ¹ represents —NR ⁴ —, —O— or —S—; X ² represents —NR ⁵ —, —O— or —S—; X ³ represents — NR ^6- , -O- or -S-; R ¹ , R ² and R ³ each represents an alkyl group, an alkenyl group, an aryl group or a heterocyclic group; R ⁴ , R ⁵ and R ⁶ are Respectively represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group. It is a cellulose acylate film manufactured by the method of any one of Claims 1-14, Comprising: The in-plane retardation Re (550) in wavelength 550nm is 5-50 nm, and the thickness direction in wavelength 550nm A cellulose acylate film having retardation Rth (550) of 90 to 150 nm. It is a cellulose acylate film manufactured by the method of any one of Claims 1-14, Comprising: The in-plane retardation Re (550) in wavelength 550nm is 5-20 nm, and the thickness direction in wavelength 550nm A cellulose acylate film having retardation Rth (550) of 90 to 150 nm. The cellulose acylate film according to claim 15 or 16, wherein the cellulose acylate film is long and has molecules of cellulose acylate oriented in a direction perpendicular to the longitudinal direction. It is a cellulose acylate film manufactured by the method of any one of Claims 1-14, Comprising: Thickness direction retardation Rth (550) in wavelength 550nm and Thickness direction retardation Rth (450) in wavelength 450nm are shown. The cellulose acylate film according to claim 15, wherein the following formula (1) is satisfied.
0.90 <Rth (450) / Rth (550) ≦ 1.5 (1) A polarizing plate comprising at least a polarizer and the cellulose acylate film according to claim 15. The polarizing plate according to claim 19, wherein an absorption axis of the polarizer and a slow axis of the cellulose acylate film are orthogonal to each other. A liquid crystal display device comprising at least the cellulose acylate film according to any one of claims 15 to 18 and / or the polarizing plate according to claim 19 or 20. The liquid crystal display device according to claim 21, wherein the liquid crystal display device is a twist alignment mode or a vertical alignment mode. An optical compensation film comprising an optically anisotropic layer comprising the cellulose acylate film according to any one of claims 15 to 18 and a composition containing a polymerizable liquid crystal compound.

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